LIBRARY 


UNIVERSITY  OF  CALIFORNIA. 


Class 


HAND-BOOK 


OF 


American 
Gas-Engineering  Practice 


BY 


M.    NISBET-LATTA 

j* 

MEMBER    AMERICAN    GAS    INSTITUTE 
MEMBER    AMERICAN    SOCIETY    OF    MECHANICAL    ENGINEERS 


NEW  YORK 

D.    VAN    NOSTRAND    COMPANY 

23  MURRAY  AND  27  WARREN  STREETS 
1907 


GENERAL 


Copyright,   1907 

BY 

IX  VAN  NOSTRAND  COMPANY 


PREFACE. 


AMERICAN  gas  engineers  have  for  a  long  time  deplored  the 
lack  of  a  work  treating  on  the  technology  of  modern  gas  supplies 
from  a  practical  standpoint,  and  framed  in  such  a  manner  as  to 
constitute  a  book  of  reference  for  those  engaged  in  the  industry, 
as  well  as  for  students. 

To  supply  his  personal  needs,  the  author  began,  several  years 
ago,  a  compilation  of  material  which,  accumulating  and  being 
classified,  has  taken  the  shape  of  the  handbook  which  he  now 
presents  to  the  profession,  with  every  confidence  that  it  will  prove 
of  value  and  be  welcomed.  His  intention  is  to  extend  and  revise 
future  editions  so  that  the  final  result  will  be  a  complete  hand- 
book of  gas  engineering,  covering  the  minute  details  of  every 
branch  of  the  industry. 

The  general  plan  of  the  work  is  as  follows: 

Water-gas  manufacture,  from  the  consideration  of  the  fuels 
and  materials  to  the  gas-holder.  The  treatment  is  throughout 
practical  rather  than  theoretical,  and  the  chapters  on  these  sub- 
jects would  be  understandingly  read  by  gas-makers,  foremen,  and 
manual  operators  of  the  works,  a  feature  which  the  author  con- 
siders of  considerable  importance.  Much  of  such  practical  detail 
of  operation  has  not  heretofore  been  published. 

The  next  division  is  devoted  to  gas  distribution,  which  is 
gone  into  at  Isn^h.  It  includes  also  a  discussion  of  the  various 
gas-burning  appliances  and  their  attendant  data,  the  whole  treated 
in  the  same  practical  way  as  the  chapters  on  manufacture. 

iii 


207115 


iv  PREFACE. 

Other  methods  of  gas  manufacture  are  reserved  for  subsequent 
editions,  but  distribution  as  here  treated  is  applicable  to  every 
field  of  gas  engineering.  Specifications  for  mains,  joints,  piping, 
and  standard  sections  will  be  found  of  peculiar  interest  and  con- 
venience. 

The  final  division  on  technical  data  contains  much  theoretical, 
mathematical,  and  technical  information  on  the  properties  of  gases 
and  steam,  calorific  values,  temperature  data,  testing  corrections, 
tables,  etc.  The  sources  of  this  data  have  been  carefully  con- 
sidered and  are  believed  to  be  reliable. 

The  subject  of  proprietary  patents  and  apparatus  not  in  general 
use  were,  for  lack  of  space,  omitted,  which  fact  also  prevented 
the  including  of  many  things  which  would  have  been  of  interest, 
these  also  being  left  for  future  editions. 

The  author  depends  on  the  readers  of  this  handbook  for  mate- 
rial assistance  in  improving  its  present  form  and  extending  its 
usefulness,  and  welcomes  any  suggestions  and  criticisms  of  his 
readers  that  may  enable  him  to  keep  the  ensuing  editions  abreast 
of  the  progress  of  the  industry. 

The  author  desires  to  acknowledge  the  assistance  of  the  many 
engineers  connected  with  gas  companies  and  manufacturing  con- 
cerns. The  uniform  courtesy  with  which  the  author's  requests  for 
information  have  been  invariably  met  is  a  source  of  much  gratifi- 
cation to  him,  and  he  desires  to  here  express  his  great  appreciation. 

M.  NISBET  LATTA. 
NEW  YORK,  August,  1907. 


CONTENTS. 


PART  I.    WATER-GAS  MANUFACTURE. 
CHAPTER  I.    THE  GENERATOR. 

PAGE 

APPARATUS 1 

FUELS,  OIL 2 

BLASTING 3 

BLOWERS 4 

BLAST  PRESSURED 5,  26 

CLINKER 0 

GENERATOR  STEAM 6 

STEAM  FLOW 9 

STEAM  SUPPLY 11 

QUALITY  OF  STEAM 12 

BARREL  CALORIMETER 43 

THROTTLING  CALORIMETER 14 

GENERATOR  DETAILS 17 

GENERATOR  OPERATION 18 

FUELS  COMPARED 19 

CARBON  DIOXIDE 22 

GENERATOR  LINING : 25 

REPAIRING  CEMENTS 26 

SAFETY  DEVICES 27 

FIRE-BRICK 27 

FIRE-CLAY  ANALYSIS 31 

CHAPTER  II.    THE  CARBURETTER. 

BRICKWORK 36 

CHECKER-BRICK  SPACING 37 

OIL  SUPPLY , 39 

v 


TO  CONTENTS. 

PAGE 

OIL-PUMP 41 

OIL  STORAGE 42 

GRADES  OF  OIL 43 

OIL  ANALYSIS 44 

TEMPERATURES 49 

GAS-MAKING  VALUE  OF  OILS 50 

OPERATION  DETAILS  .  .  51 


CHAPTER  III.    THE  SUPERHEATER. 

TEMPERATURES 53 

CARBON  DEPOSITS 54 

SUPERHEATER  BRICK 55 

CHAPTER  IV.    WASH-BOX  AND  TAR. 

CLEANING 56 

OPERATION  DETAILS 57 

COMPOSITION  OF  TAR 58 

TAR  PAINT  AND  PAVING 59 

TAR-PUMPS 60 

SEPARATION * 61 

BURNING  TAR 62 

CHAPTER  V.     SCRUBBERS. 

OPERATION  DETAILS 64 

TRAYS 64 

SPRAYS 65 

WATER  ANALYSIS 66 

CHAPTER  VI.    CONDENSERS. 

TEMPERATURES 67 

SURFACE 68 

ESSENTIAL  PRINCIPLES 69 

CHAPTER  VII.    PURIFIERS. 

TESTING  FOR  IMPURITIES 72 

SULPHUR  REMOVAL 73 

PURIFYING  MATERIAL 74 

CAPACITIES  OF  PURIFIERS 74 

MAKING  OXIDE 77 


CONTENTS.  vii 


PAGE 

PREPARING  LIME 78 

CALCULATIONS 79 

TEMPERATURE 81 

TESTING  OXIDE  BOXES 81 

REVIVIFICATION 82 

REMOVING  SULPHUR  TRACES 85 

ANALYSIS  FOR  TOTAL  SULPHUR 86 

JAEGER  GRIDS 90 


CHAPTER  VIII.    EXHAUSTERS. 

POWER  REQUIRED 92 

INSTALLATION 94 

OPERATION 94 

LOSSES 95 

SLIP 96 

AIR-COMPRESSOR  CAPACITY 99 

CAPACITY  OF  GAS-EXHAUSTERS 100 

TABLES  SHOWING  EFFECT  OF  COMPRESSION  . .                                           .  103 


CHAPTER  IX.    STATION-METERS. 

SIZES 112 

CONNECTIONS 113 

VOLUME  CORRECTION 115 

STANDARD  UNIT  OF  VOLUME 117 

OPERATION  HINTS 118 

ROTARY  METERS 119 


CHAPTER  X.     HOLDERS. 

PRESSURE 122 

FREEZING  OF  TANKS 124 

CLEANING  TANKS 125 

PATCHING  HOLDERS 125 

CAPACITY 127 

WIND  PRESSURE 129 

VARIOUS  DETAILS 130 


CHAPTER  XI.    DETAILS  OF  WORKS  OPERATION. 

QUALITY  OF  GAS 131 

OPERATION  RECORDS 132 

FLOW  OF  WATER  .  .  .133 


viii  CONTENTS. 


PART  II.     GAS  DISTRIBUTION. 
CHAPTER  XII.     NAPHTHALENE. 

FAOB 

PROPERTIES 135 

DEPOSITS 136 

REMOVING  DEPOSITS T 137 

PREVENTING  DEPOSITS 139 

CONTINUOUS  TEST : 141 

CHAPTER  XIII.    MAINS. 

CAPACITY 142 

LAYING  MAINS 143 

GRADIENT 144 

PIPE-JOINT  SPECIFICATIONS 145 

CEMENT  PIPE-JOINTS 148 

LEAD  PIPE-JOINTS » 150 

ADVANTAGES  OF  VARIOUS  JOINTS 152 

HIGH-PRESSURE  PIPE-JOINTS 154 

CAPACITY  REDUCED  BY  VALVES 159 

PRESSURE  REGULATORS 159 

DRIPS,  ANCHORS,  AND  TESTING 160 

PIPE  DEPOSITS 161 

LEAKS,  TESTING  FOR 162 

RECORDS  OF  MAINS  AND  SERVICES 163 

SERVICE  CONNECTIONS 163 

REPAIRING  BREAKS 166 

MAIN-STOPPERS 167 

COST  OF  INSTALLING  MAINS 168 

COST  OF  HANDLING  PIPE 168 

COST  OF  TRENCHING 169 

COST  OF  LAYING  PIPE 175 

COST  OF  SUBAQUEOUS  MAINS 177 

PIPE-JOINTS  OF  LEAD  WOOL 180 

SPECIAL  CASTINGS  FOR  MAINS 182 

CHAPTER  XIV.    SERVICES. 

SIZES 200 

TAPPING  FOR 200 

COATING,  PROTECTIVE 201 

FREEZING 202 

FORCING-JACKS  ..........  T .  t ...  T .  t .  T .....  t 203 


CONTENTS.  ix 

PAGE 

HIGH-PRESSURE  FITTINGS 203 

DIMENSIONS  FOR  SERVICE-PIPE 204 

HIGH-PRESSURE  MAIN  TAPPING 205 

HIGH-PRESSURE  SERVICE  CONNECTIONS 208 

CHAPTER  XV.     CONSUMERS'  METERS. 

TESTING  METERS 209 

CAPACITY  RATING 210 

CONNECTIONS 211 

COMPLAINT  AND  TEST  METERS 212 

METER-TESTING  CORRECTIONS 215 

CHAPTER  XVI.    PRESSURE. 

ADEQUATE  PRESSURE 216 

GOVERNORS 218 

PRESSURE-GAGES,  DIFFERENTIAL 219 

PITOT-TUBE  MEASUREMENTS 220 

ENGINE  PULSATIONS  IN  SUPPLY 223 

HIGH  PRESSURE,  FLOW  FORMULA 224 

COMPRESSION  OF  AIR 225 

COMPRESSION,  EFFECT  OF,  ON  GAS 226 

PRESSURE  CONVERSION  TABLES 228 

PRESSURE  STORAGE-TANKS 229 

CAPACITY  OF  PIPES  AT  VARIOUS  PRESSURES 231 

POLE'S  FORMULA  FOR  PIPE  CAPACITY 232 

COMPARISON  OF  GAS-FLOW  FORMULA 235 

CHAPTER  XVII.    HOUSE  PIPING. 

SPECIFICATIONS 236 

METERS 237 

REQUIREMENTS  FOR  GAS  FIXTURES 238 

CAPACITY  OF  PIPE 240,  247 

CONCEALED  PIPING 244 

PIPE  CEMENT 248 

CHAPTER  XVIII.    APPLIANCES. 

GAS  RANGES  AND  HEATERS 249 

TEST  FOR  EFFICIENCY 249 

BURNERS 250 

PIPING 251 

HEAT  INSULATION 252 


x  CONTENTS. 

PAGE 

GAS  CONSUMED 253 

BAKING 253 

ESSENTIALS 254 

COMBUSTION 255 

RANGE  COCKS 255 

TESTING  RANGES < 256 

RANGE  SPECIFICATIONS 259 

LIGHTING  APPLIANCES,  BURNERS '. 260 

CANDLE-POWER  AND  HEAT  VALUE 260 

HEAT  REQUIREMENT  FOR  MANTLE  BURNERS 261 

FLAT-FLAME  BURNERS 262 

INDUSTRIAL  APPLIANCES,  OPERATION 264 

CONSUMPTION  BY  VARIOUS  APPLIANCES 265 

GAS-ENGINES  . .  ...  266 


PART  III.    GENERAL  TECHNICAL  DATA. 

CHAPTER  XIX.    PROPERTIES  OF  GASES. 

COMPOSITION 267 

VOLUME,  EXPANSION  LAWS 271 

AQUEOUS  VAPOR  CORRECTIONS 275,  279 

BAROMETRIC  CORRECTIONS i 276 

SPECIFIC  GRAVITY  DETERMINATION 281 

SPECIFIC  GRAVITY  OF  OILS 285 

SPECIFIC  HEAT  OF  GASES  AND  SOLIDS 287 

CALORIFIC  VALUE  OF  GASES 291 

JUNKER  CALORIMETER 292 

SlMMANCE-ABADY  GAS-CALORIMETER 299 

TEMPERATURE  PROPERTIES 302 

MELTING-POINTS 304,  307 

OPTICAL  PYROMETER,  THE  LUNETTE 305 

UNITS  OF  HEAT  AND  TEMPERATURE 306 

INDUSTRIAL  OPERATION  TEMPERATURES 307 

HEAT  RADIATION  AND  CONDUCTION 308 

CHAPTER  XX.    STEAM. 

PROPERTIES  OF  STEAM 311 

WORK  IN  STEAM 318 

EXPANSION  CURVES 320 

SATURATED-STEAM  TABLES 323 

STEAM-BOILER  PRACTICE 325 


CONTENTS.  XI 

PAGE 

VALUE  OF  BOILER-FUELS 327 

WATER  SUPPLY  FOR  BOILERS 327 

CHIMNEYS,  DRAUGHT  AND  DIMENSIONS 332 

FLUE  AREAS 337 

CHAPTER  XXI.     MATHEMATICAL  TABLES. 

CIRCLES,  POWERS,  AND  ROOTS 341,  357 

DECIMAL  EQUIVALENTS  OF  AN  INCH 352 

LOGARITHMS  OF  CONSTANTS 352 

LOGARITHMS  OF  NUMBERS 354 

CAPACITY  TABLES  OF  VESSELS  IN  GALLONS 360 

AREAS  OF  SEMI-SQUARES 364 

CHAPTER  XXII.    CONVERSION  FACTORS. 

FRENCH  AND  ENGLISH  UNITS 368 

CONVERSION  OF  HEAT- UNITS 371 

CONVERSION  OF  TEMPERATURES 373 

FACTORS  CONCERNING  WATER 376 

CHAPTER  XXIII.    PIPE  AND  MISCELLANEOUS   DATA. 

CAPACITY  OF  IRON  PIPE  . . . : 377 

QUALITY  OF  FITTINGS 380 

DIMENSIONS  AND  WEIGHTS 383 

LEAD-PIPE  DIMENSIONS 389 

RIVETING  OF  PLATES 392 

DRILLS  AND  TAPS 399 

MISCELLANEOUS  INFORMATION 401 

SPECIFICATIONS  FOR  PIPE  AND  SPECIALS 414 

STANDARDS  FOR  PIPE  AND  SPECIALS 421 

METHOD  FOR  "  CUTTING-IN  "  SPECIALS 451 

FLEXIBLE-JOINT  PIPE 453 

TOOLS  FOR  LAYING  CAST-IRON  PIPE 456 

SIZES  OF  PURIFYING-BOXES 460 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


PART  I. 

WATER-GAS  MANUFACTURE. 


CHAPTER  I. 
THE  GENERATOR. 

THE  burden  of  this  work  will  bear  upon  water-gas  as  manu- 
factured by  the  Lowe  process,  taking  up  the  work  in  the  sequence 
of  manufacture  and  tracing  the  course  of  the  gas  throughout  the 
operation. 

Apparatus. — The  apparatus  used  is  principally  of  the  Lowe 
type,  consisting  of  a  generating  vessel,  carburetter,  superheater, 
wash-box,  condenser  and  scrubber,  relief-holder,  exhauster,  puri- 
fier, and  holder.  These  water-gas  machines  are  compact  and  the 
vessels  are  side  by  side  in  one  building. 

The  following  table  shows  the  sizes  and  capacities  of  the 
standard  Lowe  process  water-gas  apparatus  as  manufactured  by 
the  United  Gas  Improvement  Co.,  the  largest  water-gas  apparatus 
manufacturers  in  the  world: 

WATER-GAS  APPARATUS  (U.  G.  I.  CO.). 


Double 
Superheater, 
Diameter 

Generator 
Carburetter, 
Diameter 

Generator, 
Diameter 
Feet. 

Carburetter, 
Diameter 
Feet. 

Superheater, 
Diameter 
Feet. 

Daily  Capacity, 
Cubic  Feet  per 
24  Hours. 

Feet. 

Feet. 

3 

3 

3 

50,000 

4 

4 

4 

100,000 

4 

4 

4 

125,000 

5 

. 

5 

5 

5 

250,000 

6 

§ 

6 

6 

6 

400,000 

6.5 

, 

7.5 

7 

7 

750,000 

8.5 

t 

8.5 

8 

8 

1,000,000 

9 

9 

9 

9 

1,250,000 

11 

11 

11 

11 

2,000,000 

AMERICAN  GAS-ENGINEERING  PRACTICE. 


Another  variation  of  this  type  is  made  by  the  Gas  Machinery 
Co.,  who  issue  the  following  table  of  sizes.  These  capacities  are 
approximate  only,  as  the  actual  amount  of  gas  which  can  econom- 
ically be  made  in  a  carburetted  water-gas  apparatus  depends 
upon  the  kind  of  fuel  and  oil  used,  blast  pressure,  steam  supply, 
candle  power  desired,  etc. 

WATER-GAS  APPARATUS  (GAS  MACHINERY  CO.). 


Diameter 
of  Generator 
Shell,  Feet. 

Height  of 
Operating 
Floor, 
Ft.  Ins. 

Capacity  in 
24 

Cubic  Feet  per 
Hours. 

Size  of 
Building 
Suitable  for 
Two  Sets, 

Usual  Height 
of  Building 
to  Bottom  of 
Roof-trusses, 

Feet. 

Feet. 

3.5 

12     3 

60,000 

to        75,000 

23X30 

20 

4 

13     3 

100,000 

125,000 

24X32 

22 

5 

13     3 

175,000 

250,000 

27X40 

25 

6 

14     3 

325,000 

425,000 

30X46 

28 

7 

14     3 

500,000 

650,000 

33X52 

30 

8 

14     3 

750,000 

900,000 

36X56 

30 

9 

15     3 

1,000,000 

1,250,000 

38X64 

30 

10 

16     3 

1,300,000 

1,600,000 

42X78 

32 

11 

16     3 

1,600,000 

1,900,000 

48X84 

32 

Fuels. — Generator  fuels  are  generally  of  two  kinds:  coal 
(anthracite)  and  what  is  generally  known  as  48-hour  oven  coke. 
The  best  results  from  either  of  these  are  generally  obtained  from 
a  glossy  black  coal,  egg-size  and  passing  through  about  a  3-inc'h- 
mesh  screen,  or  from  a  silvery-gray  coke  of  about  the  same  diam- 
eter. The  chief  defect  which  the  coal  may  possess  lies  in  the 
amount  of  sulphur  which  it  contains,  a  large  percentage  of  sulphur 
producing  not  only  a  very  sulphurous  gas,  but  also  forming  a  hard 
and  intractable  clinker.  "  Twenty-four-hour  gas-house  coke  "  is 
sometimes  used  in  emergency,  but  coke  of  this  class  is  usually  too 
soft  and  does  not  retain  the  heat  in  the  generator  while  steam 
is  blown  through  it  during  the  "  run,"  thereby  creating  a  strongly 
acid  gas. 

Oil. — It  is  the  custom  of  a  number  of  companies  throughout 
the  country  to  introduce  the  oil  used  for  enriching  the  water-gas 
directly  into  the  generator  on  all  up-runs.  This  is  supposed  to 
save  the  brick  of  the  carburetter,  and,  inasmuch  as  the  oil  is 
vaporized  at  the  same  heat  and  under  the  same  conditions  under 
which  the  steam  is  decomposed,  the  vapor  tension  is  assumed 
to  be  approximately  the  same,  and  the  oil-gas  and  water-gas  being 
thus  combined  under  similar  conditions  at  an  equal  temperature 
form  a  more  intimate  mixture.  In  addition  to  this,  when  the 


THE  GENERATOR.  3 

gases  are  formed  in  the  generator  the  carburetter  is  saved  the 
chilling  effect  due  to  vaporizing  the  oil,  and  is  thus  utilized  as  an 
additional  superheating  chamber,  providing  for  the  gases  an  extraor- 
dinary amount  of  fixing  surface  and  prolonging  the  period  of  fixation 
travel. 

Practice  differs  very  greatly  in  regard  to  this  method  of  work- 
ing. It  is  certain,  however,  that  in  small  works  occasional  use  of 
this  method  is  of  advantage,  inasmuch  as  it  not  only  relieves  the 
carburetter  of  the  immediate  vaporization  of  the  oil,  but  allows 
any  carbon  which  may  have  already  accumulated  upon  the  brick- 
work of  the  carburetter  to  burn  off.  There  should  be,  at  least  in 
all  small  works  where  continuous  running  is  a  necessity  and  any 
delay  caused  by  stoppage  of  the  oil-spray  is  a  serious  contin- 
gency, a  flexible  connection  with  the  oil-pipe  which  can  be 
attached  to  a  spray  tapped  into  the  lid  of  the  generator  coaling- 
valve  cover. 

Where  oil  is  used  to  substitute  solid  fuel  in  manufacturing 
water-gas,  the  amount  necessary,  using  crude  oil  as  a  basis,  is 
variously  estimated  at  from  12  to  15  gallons  per  1000  cu.  ft.  At 
least  one-third  of  this  oil  is  consumed  for  the  heating  (or  during 
the  blasting  period)  of  the  apparatus. 

Blasting. — The  question  of  the  coaling  periodicity  is  one  over 
which  there  is  considerable  diversity  of  opinion.  It  should  un- 
doubtedly depend  upon  the  condition  of  the  incandescent  fuel- 
bed  and  be  determined  by  the  gas-maker.  The  fires  should  be 
thoroughly  cleaned  and  freed  of  all  possible  clinker  at  least  twice 
a  day.  In  blowing  air  through  the  fuel-bed  during  the  first  blast- 
ing, in  putting  a  generator  in  operation,  many  analyses  of  gas 
show  that  it  is  a  rare  thing  for  the  generator  fire  to  be  thoroughly 
in  condition  for  the  first  run,  the  result  invariably  showing  large 
quantities  of  carbon  dioxide,  and  going  to  prove  that  the  dura- 
tion of  the  blast  was  too  short. 

The  author  has  indeed  never  known  a  gas-maker  who  was 
sufficiently  careful  when  getting  up  this  first  heat,  and  especially 
recommends  that  before  turning  on  steam  the  coaling-valve  be 
opened  and  the  fire  examined  to  see  that  there  is  no  " green" 
coal  visible  which  has  not  attained  the  proper  heat,  and  that 
the  generator  fuel-bed  has  a  temperature  corresponding  to  a 
bright  orange  color.  Gas-makers  are  often  prevented  from  suffi- 
ciently blasting  their  generators  for  fear  of  overheating  the  other 
chambers.  It  is  better  to  operate  with  a  light  blast  for  a  longer 
period  through  the  generator  than  with  a  strong  blast  for  a  shorter 
time,  and  under  some  conditions  it  has  been  advisable  to  put  a 
light  blast  through  the  generator  with  the  coaling-valve  remain- 
ing open.  Should,  however,  the  carburetter  become  unduly  hot 


AMERICAN  GAS-ENGINEERING   PRACTICE. 

during  this  blasting  period  it  may  be  " blown  cold"  by  an  exces- 
sive blast  through  the  carburetter  while  a  light  generator  blast 
is  maintained. 

There  cannot  be  too  much  emphasis  laid  upon  the  proper 
heat  being  obtained  in  the  generator  before  the  commencement 
of  runs,  as  insufficient  heat  and  improper  decomposition  of  the 
steam,  together  with  the  chilling  effect  of  "  green  "  or  insuffi- 
ciently heated  coal,  will  invariably  produce  an  excess  of  oxygen, 
while  the  carbon,  unless  incandescent,  fails  to  combine,  thereby 
forming  carbon  dioxide  instead  of  the  desired  monoxide. 

Blowers. — Blowers  should  be  of  ample  capacity  and  if  pos- 
sible in  duplicate.  The  location  of  a  blower  should  be  removed  as 
far  as  possible  from  dust,  as  its  bearings  at  high  speeds  require 
close  attention  and  should  be  kept  in  the  very  best  con- 
dition, their  oilways  being  examined  periodically,  for  they  may 
perhaps  be  termed  the  "  critical  point  "  of  the  works.  It  is  some- 
times necessary,  in  case  of  their  heating,  to  play  a  small  stream  of 
water  upon  them;  ice  may  be  of  advantage;  cylinder-oil,  castor- 
oil,  or  even  urine  is  used,  the  latter  being  employed  with  most 
remarkable  results,  as  the  salts  therein  contained  crystallize  in 
the  heat  and  form  a  viscous  bearing  between  the  shaft  and  the 
box.  Dixon's  graphite  compounds  are  also  valuable. 

The  following  table  gives  the  principal  dimensions  to  be  speci- 
fied in  securing  a  blower  of  the  Sturtevant  type  for  supplying  air- 
blast  to  water-gas  generators;  they  are  special  extra  heavy: 


DIMENSIONS  OF  BLOWERS. 


Maximum 

Blower  on  Adjustable  Bed 

Pressure. 

with  Sliding  Outlet. 

Diameter 

Maxi- 

Blower 

Number 
of 
Blower. 

and  Face 
of  Pulley 
in  Inches. 

mum 
Revolu- 
tions per 
Minute. 

Ounces 
per 
Square 
Inch. 

Inches 
of 
Water. 

only. 
Outside 
Diameter 
of  Outlet 
in  Inches. 

Outside 
Diameter 
Outlet  with 
Horizontal 
Discharge 

Dimensions  of 
Oblong  Pipe 
Connection  for 
Up-blast 
Discharge  in 

in  Inches. 

Inches. 

4 

5X  7 

3,670 

12 

20.8 

10f 

Hf 

10fXl5f 

5 

7X  8 

3,420 

14 

24.2 

12 

1*1 

12iXl8t 

6 

8X9 

3,330 

16 

27.7 

14 

16} 

14fx21f 

7 

9X11 

2,750 

16 

27.7 

16 

171 

16|X24f 

8 

10X13 

2,270 

16 

27.7 

ISj 

20f 

18|X27| 

9 

12X15 

2,040 

16 

27.7 

21 

23i 

21fX32£ 

10 

14X16 

1,700 

16 

27.7 

24 

25| 

24|X36| 

NOTE. — These  Sturtevant  special  extra-heavy  blowers  are  for  supplying  blast  to  water- 
gas  generators. 


THE  GENERATOR.  5 

The  outside  dimensions  of  the  shells  of  these  blowers  are  the 
same  as  those  of  the  ordinary  gas-blowers  given  in  Catalogue  No. 
82,  but  the  pulleys  are  larger  and  the  hangers  or  supports  for  the 
bearings  are  longer. 

Bearings  of  the  blower  or  engine,  where  made  of  babbitt  metal, 
should  be  made  at  a  single  pouring  of  the  metal,  no  interval 
being  allowed.  After  being  poured,  the  bearing  should  be  heavily 
peened,  this  having  a  tendency  to  make  the  metal  in  the  bearing 
more  homogeneous.  Where  engine  or  blower  bearings  have  a 
tendency  to  run  hot,  cylinder-oil  or,  better,  castor-oil  may  be 
temporarily  used.  At  the  first  opportunity,  however,  the  bear- 
ings should  be  opened  and  the  oil-ducts  examined. 

Generator  Blast  Pressures.  —  The  difference  in  pressure 
between  the  top  and  bottom  of  a  water-gas  generator  having  a 
6  to  7  ft.  deep  fuel-bed  will  vary  from  5  in.  to  8  in.,  depending  upon 
the  nature  of  the  fuel  used  and  the  heat  in  the  machine.  Six 
inches  pressure  is  a  good  average,  while  a  lesser  difference  than 
5  in.  tends  to  show  a  lack  of  even  distribution  on  the  part  of  the 
fire-bed,  the  presence  of  blow-holes,  etc. 

High  blast  pressure  has  a  tendency  to  increase  clinkers;  when 
necessary  this  may  be  counteracted  by  alternating  or  reversing 
the  steam  in  the  middle  of  each  run.  Too  much  stress  cannot  be 
laid  upon  the  necessity  for  a  thorough  cleaning  of  the  fire,  a  neglect 
of  this,  more  than  any  other  feature,  tending  toward  clinker  forma- 
tion. Where  generators  are  intermittently  in  service  they  should 
be  gradually  brought  up  to  their  heat,  the  increase  in  temperature 
being  by  slow  degrees  and  not  forced.  From  a  standpoint  of  pro- 
duction it  is  not  good  practice  to  vary  the  direction  of  steam  during 
a  run,  except  in  instances  of  excessive  clinker  formation,  greater 
production  being  obtained  per  hour  by  varying  the  alternate  runs 
by  a  down-run  every  third  or  fourth  time. 

Where  fan-blowers  are  driven  by  electricity  common  practice 
demands  a  consumption  of  about  1  k.w.  per  1000  cu.  ft.  of  gas 
manufactured. 

Regarding  the  pressure  of  blast  to  be  maintained  upon  the 
generator  of  water-gas  sets,  the  following  theory  has  been  the 
result  of  a  number  of  experiments  by  the  author: 

A  medium  blast  pressure  should  as  nearly  as  possible  be  main- 
tained because,  should  the  blast  pressure  increase  above  about 
18  in.,  combustion  of  fuel  becomes  too  rapid,  producing  too  much 
heat  and  too  rapid  consumption  of  fuel,  together  with  clinker. 
Should  the^blast  pressure  fall  below  the  minimum,  about  12  in. 
of  water,  the  following  phenomena  will  be  observed: 

The  rate  of  flow  of  the  blast  being  insufficient  in  pressure  to 
carry  away  from  the  generator  the  CO  first  produced  by  com  bus- 


AMERICAN  GAS-ENGINEERING  PRACTICE. 

tion,  and  which  should  be  burned  to  CO2  by  the  additional  air 
supply  provided  at  the  carburetter  and  superheater,  furnishing 
fuel  respectively  to  these  parts  of  the  apparatus,  a  large  portion 
of  this  product  remains  inertly  in  the  generator  and  is  gradually 
burned  from  CO  to  CO2,  or,  in  other  words,  the  complete  com- 
bustion of  C  to  CO2  takes  place  in  the  generator  instead  of  being 
distributed  throughout  the  apparatus.  Primary  combustion  should 
take  place  in  the  generator,  and  secondary  combustion  in  the 
two  machines  following  in  series. 

The  result  of  this  additional  combustion  is  the  production  of 
excessive  heat  in  the  generator,  greatly  deteriorating  the  lining, 
etc.,  and  at  the  same  time  causes  a  failure  on  the  part  of  the  gen- 
erator to  supply  sufficient  gas  for  the  secondary  combustion  of  the 
other  machines.  When  the  blast  pressure  is  ample  these  gases  are 
kept  moving  and  carried  along^by  the  draught,  and  are  in  due  pro- 
cess consumed.  The  capacity  of  the  generator  is  usually  rated 
from  the  area  of  the  grate,  being  generally  figured  approximately 
at  20,000  cubic  feet  per  square  foot  of  grate  surface  per  24  hours. 

It  is  recommended  in  all  instances  to  run  the  steam-pipe  to  the 
generator,  of  a  size  not  smaller  than  1.5  in.  diameter,  reducing  it 
at  the  generator  inlet  by.  a  J-in.  valve. 

Clinker. — A  word  may  be  said  here  concerning  one  of  the 
greatest  annoyances  to  the  gas-maker,  as  well  as  hindrance  to 
obtaining  good  results — the  formation  of  clinker,  which  occurs 
especially  with  highly  sulphurous  coals  and  is  at  times  almost  im- 
possible to  control.  Besides  the  use  of  heavy  clinkering-bars,  long- 
handle  cold  chisels,  and  sledges,  there  are  numerous  chemical  com- 
pounds used  for  clinker  disintegration.  Oyster-shells  and  unslaked 
lime  are  used  for  this  purpose  in  a  large  number  of  works,  but  are 
not  especially  efficacious.  Perhaps  one  of  the  surest  methods  is 
that  of  leaving  the  steam  turned  on  upon  the  bottom  of  the  gen- 
erator with  the  valve  opened,  say,  a  quarter  of  a  turn.  This  method, 
if  pursued  for  ten  or  twelve  hours,  invariably  softens  the  clinker 
and  is  generally  known  as  "rotting."  Its  one  objection  is  the 
softening  and  decomposition  of  the  fire-brick. 

The  author  suggests  a  method  having  none  of  these  disadvan- 
tages and  which  he  has  used  with  invariable  success.  On  the  end 
of  a  pipe  of  about  f  in.  diameter  and  12  or  15  ft.  in  length  he  affixes 
a  funnel,  places  the  end  of  the  pipe  upon  a  clinker,  where  it  joins 
the  fire-brick  and  pours  through  the  funnel  a  mixture  of  12  pints 
of  water  and  1  of  common  vinegar,  moving  the  pipe  about  to 
attack  various  points  of  the  clinker  and  repeating  the  pouring, 
when  it  becomes  soft  enough  to  yield  to  a  heavy  clinker-bar. 

Generator  Steam. — It  has  been  generally  agreed  that  the 
temperature  of  the  fire,  which  should  be  at  least  1800°  F.,  and  the 


THE  GENERATOR.  7 

control  of  the  rate  of  flow  of  the  steam  determine  the  composition 
of  the  gas  within  the  limits  usually  applied  to  water-gas  practice. 
It  is  doubtless  nearly  correct  to  assume  the  amount  of  steam  dis- 
sociated as  about  15.4  or  15.5  Ibs.  per  1000  cu.  ft.  of  final  gas. 

The  steam  should  unquestionably  be  as  dry  as  possible,  and  for 
this  purpose  the  initial  boiler  pressure  should  be  not  lower  than 
90  and  not  exceeding  120  Ibs.  All  steam-piping  should  be  cov- 
ered, preferably  with  magnesia  covering.  A  separator  should  be 
placed  near  the  entrance  of  the  generator,  an  extremely  satisfactory 
kind  of  which  is  the  Cochrane  horizontal  type;  connected  with 
this,  the  Bundy  steam-trap  has  given  the  author  the  best  results. 
This  trap  is  perfectly  automatic,  easily  adjusted,  and  operates 
with  a  balance-arm;  one  alone  will  take  care  of  the  water  from 
a  half-dozen  or  more  separators  about  the  works  and,  if  placed 
at  the  proper  elevation,  will  return  condensation  into  the  boiler. 

One  of  the  greatest  difficulties  in  the  manufacture  of  gas  is 
the  proper  regulation  of  the  amount  of  steam  to  be  admitted  into 
the  generator.  Too  little  steam  retards  gas  production  or  limits 
the  amount  of  gas  made  by  the  generator,  while  an  excess  of  steam 
carries  off  and  wastes  an  enormous  amount  of  heat  from  the  gen- 
erator fire,  the  exact  amount  depending  upon  the  temperature  of 
the  gas  when  leaving  the  superheater.  For  example,  suppose  the 
steam  entered  the  generator  at  331°  F.  and  the  gas  left  the  super- 
heater at  1450°  F.,  then  each  pound  of  undecomposed  steam  car- 
ried from  the  superheater  about  537  B.t.u.  Assuming  the  quantity 
of  waste  steam  to  amount  (as  has  been  cited  in  an  experiment  by 
Mr.  Morris)  to  14.8  Ibs.  per  1000  cu.  ft.  of  gas,  the  waste  heat  per 
1000  cu.  ft.  manufactured  would  amount  to  nearly  8000  B.t.u.,  or 
about  one-half  of  the  total  energy  required  for  the  decomposing  of 
the  steam  in  the  finished  gas. 

Too  little  steam  will  leave  the  fire  in  a  condition  favorable  to 
the  formation  of  hard  and  obdurate  clinker,  greatly  increasing 
the  length  of  the  necessary  cleaning  period  and  reducing  materi- 
ally the  gas  made  per  day  for  the  apparatus,  and  destroying  the 
linings. 

The  quantity  of  excess  steam  (steam  admitted  to  the  generator 
and  not  decomposed)  is  best  determined  by  an  analysis  of  the 
gas  for  CO2,  the  amount  of  carbonic  acid  gas  being  in  direct  ratio 
to  the  excess  of  steam. 

To  determine  the  rate  of  flow  of  steam  admitted  to  the  genera- 
tor satisfactory  use  may  be  made  of  the  following  device.  The 
steam-pipe  is  disconnected  from  the  generator  shell  and  immersed 
in  a  cask  containing  a  known  .weight  of  water,  the  cask  being  set 
upon  portable  scales,  so  that  the  steam-pipe  dips  into  the  water 
the  number  of  inches  corresponding  to  the  gas  pressure  in  the 


8  AMERICAN  GAS-ENGINEERING  PRACTICE. 

generator  when  and  where  the  steam  is  admitted.  The  total 
length  of  steam-piping  and  total  length  of  turns  are  the  same  as 
when  the  pipe  is  connected  to  the  generator,  and  the  quantity  of 
steam  flowing  into  the  cask  per  unit  of  time  is  read  on  the  scale- 
beam.  Separate  determinations  are  made  of  the  steam  supplies 
at  the  upper  and  lower  connections  to  the  generator.  The  rates 
thus  found  may  be  taken  as  approximately  correct  for  conditions 
of  actual  generator  use. 

Under  operating  conditions  the  use  of  the  Sargent  Steam 
Meter  will  be  found  very  convenient  for  current  reference,  and 
as  a  standard  of  comparison  and  of  operation. 

This  meter  is  tested  and  calibrated  with  commercially  dry 
steam  containing  about  2%  of  moisture,  and  of  course  any  varia- 
tion in  this  moisture  shows  up  as  an  error.  To  all  practical  pur- 
poses however,  allowing  for  the  personal  error  possible  in  obser- 
vation, under  any  ordinary  conditions  of  operation,  the  maxi- 
mum variation  of  this  meter  does  not  exceed  3%,  which  is  near 
enough  to  furnish  a  very  satisfactory  standard  of  operation  and 
comparison. 

The  operation  of  the  meter  is  as  follows:  When  no  steam  is 
flowing  through  the  pipe  the  mercury  in  the  cistern  and  in  the 
tube  is  on  a  level,  that  in  the  tube  registering  zero.  The  steam 
beginning  to  flow,  its  velocity  places  a  pressure  upon  the  cistern, 
causing  the  mercury  to  rise  in  the  tube  in  direct  ratio  to  said 
velocity  and  proportionate  to  the  weight  flowing  through. 

To  read  the  meter:  Note  the  pressure  on  the  gauge,  revolve 
the  drum  containing  the  dial,  by  the  hand-wheel,  until  the  pres- 
sure on  the  top  of  the  drum  corresponding  to  the  gauge  is  behind 
the  tube,  then  the  top  of  the  column  of  mercury  will  indicate 
the  pounds  of  steam  or  horse-power  flowing  through  per  unit  of 
time. 

The  quantity  of  steam  decomposed,  and  so  present  in  the 
finished  gas,  is  determined  from  an  analysis  of  the  gas,  the  water- 
vapor  present  in  the  finished  gas  being  dependent  upon  the  tem- 
perature. 

A  direct  measure  of  the  excess  steam  used  per  1000  cu.  ft.  of 
gas  made  is  effected  by  collecting  all  the  condensation  (tar  and 
water)  that  occurs.  If  no  water  is  introduced  into  the  system 
between  the  carburetter  and  the  gas-holder,  the  water  condensed 
and  measured  gives  directly  the  data  for  the  excess  steam  used  in 
the  generator.  This  figure  is  one  most  easily  and  accurately  ascer- 
tained, and  it  furnishes  a  constant  check  upon  the  operation  of 
the  generator. 

It  is  needless  to  point  out  that  wet  steam  carrying  with  it 
water  in  the  form  of  fog  would  largely  increase  the  oxygen  factor 


THE  GENERATOR.  9 

in  the  gas,  thereby  running  up  the  production  of  CO2.  To  over- 
come this  it  is  necessary,  as  before  stated,  to  procure  the  dryest 
possible  steam  by  using  pipe  coverings,  steam  separators,  and  a 
high  initial  boiler  pressure.  On  the  other  hand  this  boiler  pressure 
has  certain  drawbacks,  of  which  rapidity  of  flow  of  the  steam 
through  the  incandescent  carbon  is  the  chief.  Too  great  a  velocity 
will  produce  blow-holes  or  open  channels  through  the  carbon  bed 
and  cause  the  steam  to  escape  undecomposed,  as  well  as  an  uneven 
distribution  of  steam  throughout  the  fuel-bed,  which,  for  the  best 
results,  should  be  as  uniform  as  possible.  To  overcome  these  diffi- 
culties it  has  occurred  to  the  writer  to  place  a  reduc ing-valve  (such 
as  the  Mason  type)  on  the  steam-pipe  just  prior  to  its  admission 
into  the  separator;  such  a  valve  will  reduce  a  pressure  of  about 
100  Ibs.  at  the  boiler  to  a  terminal  pressure  of  45  or  50  Ibs.  in  the 
generator,  which  would  materially  reduce  the  velocity  of  flow 
and  tend  to  superheat. 

It  has  also  occurred  to  the  writer  that  it  might  be  well  to  intro- 
duce the  steam  into  the  generator  by  a  number  of  small  jets  similar 
to  the  radial  sprays  on  scrubbers,  which  would  distribute  the 
steam  more  generally  over  the  cross-section  of  the  generator.  He 
has,  however,  no  information  as  to  any  such  experiment  having 
ever  been  made.  However,  it  is  well  known  in  gas  manufacture 
that  decreasing  velocity  of  gas  flow  increases  the  intimate  union 
and  thorough  combination  of  the  substances  involved. 

It  is  needless  to  point  out  the  necessity  of  having  extra-heavy 
pipe  and  heavy  brass  fittings  on  all  steam  connections.  In  the  case 
of  both  oil  and  steam  connections  the  author  has  had  specially 
good  service  from  Lunkenheimer  valves.  Between  the  generator 
and  the  carburetter  asbestos-board  gaskets  should  be  used  in  the 
connections,  and  for  these  and  other  packings  there  is  none  better 
than  Vulcabeston. 

Steam  Flow. — Drs.  Strache  and  R.  Jahoda,  in  their  work  on 
the  "  Theory  of  the  Water-gas  Process/'  place  great  emphasis  on 
the  rate  of  flow  of  the  steam,  and  imply  that  Dr.  Bunte  in  his  work 
did  not  properly  appreciate  the.  result  that  different  rates  of  flow 
would  have  upon  the  gas  made  thereby.  Among  other  remarks 
they  write  as  follows:  That  at  a  particular  temperature  both  the 
steam  passing  through  undecomposed  and  the  proportion  of  car- 
bonic acid  in  the  gas  largely  increase  with  the  increase  in  the  rate 
of  the  steam  flow,  and  also  increase  in  direct  ratio.  Secondly, 
that,  a  constant  rate  of  flow  of  the  steam  being  secured,  both  the 
CO2  and  the  steam  excess  decrease  with  an  increase  of  tempera- 
ture. That  at  low  temperature  the  CO2  and  the  excess  may  be 
reduced  by  reducing  tbe  rate  of  flow  of  the  steam. 

In  verification  of  the  above  they  give  the  following  table: 


10 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


Rate  of 
Flow  of 
Steam. 

Hinute  of 
Run  at 
which  Ob- 
servation 
was  Made. 

Temper- 
ature of 
Generator, 
Deg.  C. 

Temper- 
ature of 
Effluent 
Gas, 
Deg.  C. 

Unde- 
composed 
Steam, 
Percent- 
age of 
Total. 

Carbonic 
Acid  Gas, 
Per  Cent. 

Efficiency 
of  Run, 
Per  Cent, 
of  Maxi- 
mum. 

Total 
Efficiency, 
Per  Cent, 
of  Maxi- 
mum. 

0.58 

2 

790 

228 

1.3 

7.1 

5 

788 

207 

2.7 

4.6 

69^6 

54.5 

12 

785 

214 

9.1 

6.2 

67.0 

53.0 

20 

778 

221 

21.8 

8.9 

60.5 

47.0 

35 

740 

200 

48.8 

13.0 

42.0 

33.0 

4.40 

1 

860 

390 

4.0 

2.2 

92.0 

75.0 

3 

850 

390 

10.0 

2.7 

91.0 

74.0 

6 

816 

365 

22.0 

4.5 

90.0 

75.0 

9 

810 

365 

24.0 

6.6 

88.0 

73.5 

12 

796 

408 

28.0 

8.7 

86.3 

71.8 

16 

775 

415 

45.5 

11.4 

83.5 

71.0 

7.50 

1 

530 

2.7 

3 

515 

11.7 

4.6 

90'6 

69^6 

6 

490 

27.4 

9.6 

88.0 

70.5 

9 

470 

54.2 

12.6 

78.0 

63.0 

12 

470 

62.1 

15.6 

73.0 

59.0 

8.10 

1 

515 

3.4 

3 

510 

'l'.3 

5.5 

9i"o 

71.0 

6 

. 

500 

19.7 

11.2 

88.0 

70.0 

9 

. 

475 

14.9 

86.0 

71.0 

12 

470 

47'.9 

17.3 

82.0 

68.0 

13.00 

1 

470 

7.6 

3.4 

92.0 

73.5 

5 

500 

11.9 

5.6 

91  .5 

73.0 

6 

500 

32.1 

9.0 

92.0 

71.5 

13.40 

1 

900 

470 

14.3 

5.0 

91.5 

72.5 

3 

8$0 

478 

27.9 

6.9 

89.0 

71.0 

6 

830 

475 

48.9 

9.4 

84.0 

67.5 

9 

800 

493 

62.8 

13.1 

77.0 

62.5 

12 

780 

492 

69.6 

13.9 

74.0 

60.0 

17.00 

1 

600 

8.1 

2.6 

91.0 

69.0 

3 

590 

25.8 

5.3 

88.0 

67.0 

6 

560 

48.5 

11.8 

81.0 

62.0 

10 

540 

73.6 

14.9 

67.5 

51.0 

12 

530 

76.5 

15.2 

65.0 

51.0 

21.20 

1 

945 

680 

8.6 

4.4 

90.5 

70.5 

3 

910 

650 

41.3 

6.8 

83.0 

63.0 

6 

865 

620 

48.6 

8.7 

81.0 

61.5 

12 

805 

590 

70.1 

14.4 

68.5 

53.5 

16 

780 

77.6 

17.6 

61.5 

47.0 

21.30 

1 

680 

2.1 

3 

650 

23^0 

6.0 

90'.0 

70'.5 

6 

620 

63.3 

11.8 

72.5 

54.0 

10 

... 

595 

77.1 

14.8 

61.5 

46.0 

THE   GENERATOR. 


11 


The  researches  of  Harris  under  the  direction  of  Dr.  Bunte  were 
tabulated  as  follows: 


Temperature, 

Composition  of  Gas,  Volumes  Per  Cent. 

Water-vapor,  Per  Cent. 

Degrees  C. 

H 

CO. 

C02. 

Decomposed. 

Undecomposed  . 

694 

65.2 

4.9 

29.8 

8.8 

91.2 

758 

65.2 

7.8 

27.0 

25.3 

74.7 

838 

62.4 

13.1 

24.5 

34.7 

65.3 

838 

61.9 

15.1 

22.9 

41.0 

59.0 

861 

59.9 

18.1 

21.9 

48.2 

51.8 

954 

53.3 

39.3 

6.8 

70.2 

27.2 

1010 

48.8 

49.7 

1.5 

94.0 

6.0 

1060 

50.7 

48.0 

1.3 

93.0 

7.0 

1127 

50.9 

48.5 

0.6 

99.4 

0.6 

Steam  Supply. — Steam  should  never  be  turned  on  the  gen- 
erator for  a  "  run  "  until  the  top  of  the  fire  appears  to  be  in  a 
thorough  state  of  combustion  and  free  from  dark  (or  "  green  ") 
coal,  as  viewed  through  the  sight-cock  in  the  coaling-lid  of  the 
generator. 

Excessive  heat  in  the  generator,  and  indirectly  the  entire  set, 
may  be  speedily  "  killed  "  by  adding,  in  addition  to  the  regular 
up-steam  on  an  up-run,  say  a  quarter  of  a  turn  of  opening  on  the 
down-steam  valve.  It  may  also  be  reduced  by  varying  the  amount 
or  period  of  the  blast,  or,  conversely,  the  variation  of  the  regular 
steam  admitted. 

The  percentage  of  gain  resulting  from  the  increased  tempera- 
ture of  feed-water  in  any  particular  case  may  be  calculated  by  the 
formula 


Gain  (per  cent.)  = 


100(!T-0 
H-t     ' 


where  H  =  total  heat  in  steam  at  boiler  pressure,  reckoned  from  0°  F. ; 
T=  temperature  of  feed-water  after  heating; 
t  =  temperature  of  feed-water  before  heating. 

The  quality  of  the  steam  supplied  is  quite  important,  the  prop- 
erties being  as  follows : 

Saturated  Steam. — Saturated  steam  is  steam  in  contact  with 
and  containing  entrained  water  at  the  same  temperature  as  the 
steam  itself.  The  name  may  be  also  applied  to  the  steam  on 
the  point  of  condensation,  even  when  this  steam  is  to  all  appear- 
ances perfectly  "dry  "  (not  containing  water  in  mechanical  sus- 
pension), as  long  as  the  pressure  and  temperature  remain  un- 


12  AMERICAN  GAS-ENGINEERING  PRACTICE. 

changed;  but  the  slightest  change  in  either  of  these  two  con- 
ditions will  cause  condensation  on  the  part  of  a  portion  of  the 
steam.  Therefore,  should  a  given  volume  of  saturated  steam  be 
made  to  occupy  a  smaller  space,  the  temperature  remaining  un- 
changed, the  pressure  will  also  remain  unchanged,  as  enough  of 
the  steam  will  be  condensed  in  the  water  to  equalize  the  reduc- 
tion of  volume  by  the  change  of  space  occupied.  Saturated 
steam  is  therefore  not  a  permanent  gas,  inasmuch  as  it  cannot 
be  compressed  under  a  constant  temperature  without  a  change 
resulting  to  its  physical  nature. 

Superheated  Steam. — A  good  definition  of  superheated  steam 
is  as  follows:  "  Steam  which  for  the  same  pressure  has  a  greater 
temperature,  and  for  any  particular  weight  a  greater  volume,  than 
saturated  steam  at  the  same  pressure."  It  is  produced  by  the 
vaporizing  or  gasifying  of  the  water  out  of  the  steam  molecule 
of  saturated  steam.  Therefore^,  if  its  pressure  is  kept  constant 
it  tends  to  expand  as  its  temperature  increases.  In  some  respects 
it  is  thus  similar  to  a  permanent  gas;  that  is,  if  compressed 
under  constant  temperature,  the  pressure  will  at  first  increase 
inversely  as  the  volume.  This  is,  however,  within  limits;  for,  as 
the  compression  continues,  the  steam  finally  reaches  the  point  of 
saturation,  and  thereafter  the  pressure  cannot  be  increased  by  fur- 
ther compression  under  a  constant  temperature. 

The  chief  difficulty  in  the  generation  of  superheated  steam  is 
to  secure  material  for  the  superheater  which  will  withstand  the 
intense  heat  of  the  burning  gases  on  the  one  side  and  the  steam 
on  the  other.  This  difficulty  has  made  its  general  use  hitherto 
impracticable.  Generally  speaking,  horizontal  boilers  produce  steam 
strongly  saturated,  while  vertical  boilers 
have  a  tendency  towards  superheating. 

Quality  of  Steam. — The  quality  of 
steam  depends  upon  the  quantity  of  heat 
it  contains.  It  is  wet  if  it  contains  fog 
or  drops  of  water,  dry  if  it  contains  just 
enough  heat  to  keep  it  so,  and  super- 
heated when  it  contains  more  heat  than 
FIG.  1. -Steam  Sampling-  nece  to  do  go  Thus  if  a  gam  le  of 

K 1 M^?  •  •I'll  11 

steam  is  obtained  and  condensed,  measur- 
ing the  heat  given  up  and  the  water  produced,  the  B.t.u.  per  pound 
of  water  can  readily  be  calculated.  The  process  by  which  this 
test  is  made  is  called  steam  calorimetry  and  the  apparatus  is  a 
calorimeter.  The  throttling  calorimeters  are  more  accurate  for 
steam  containing  very  little  moisture  and  superheated  steam,  but 
the  separating  calorimeter  is  best  for  general  purposes.  To  obtain 
a  sample  of  steam  the  steam-pipe  is  tapped  and  a  sampling-pipe 


THE  GENERATOR. 


13 


with  a  long  thread  screwed  in  until  the  end  reaches  the  center  of 
the  steam-pipe.  In  the  condensing  types  the  weight  of  the  ap- 
paratus and  its  specific  heat  must  be  known.  This  is  obtained  by 
adding  a  known  weight  of  heated  water,  noting  the  rise  in  tem- 
perature, and  what  it  should  have  been  if  the  temperature  of  the 
water  alone  were  considered.  The  difference  divided  by  the  final 
temperature  and  multiplied  by  the  weight  of  the  water  will  give 
the  water  equivalent  of  the  calorimeter  vessel  which  must  be 
added  to  that  of  the  water  in  the  vessel. 

Barrel  Calorimeter.— This  consists  of  a  platform  scales  on 
which  is  a  barrel  into  which  dips  a  steam-pipe  perforated  near  the 
bottom.  The  barrel  should  be  large 
enough  to  hold  450  Ibs.  of  water, 
although  only  about  360  Ibs.  are  put 
into  it.  First  let  steam  enter  until 
the  temperature  of  the  water  is 
about  130°  F.  to  warm  the  barrel; 
empty  it  and  add  exactly  360  Ibs. 
of  water,  taking  its  temperature  im- 
mediately, removing  the  steam- 
pipe  and  hose  and  warming  it  up 
with  steam;  insert  again  into  the 
water  and  note  the  temperature  of 
the  water  until  it  is  about  110°  F., 
when  the  steam  must  be  turned  off 
and  the  weight  noted  as  well  as  the  temperature.  The  increased 
weight  will  be  due  to  the  weight  of  steam  condensed,  and  the 
increased  temperature  to  the  heat  held  by  the  steam.  The  quality 
of  the  steam  is  then  found  by  the  following  formula: 


FIG.  2. — Barrel  Calorimeter. 


where   Q  =  proportion  by  weight  of  pure  dry  steam  in  the  sample; 
d  —  weight  of  dry  steam  in  the  sample  condensed; 
W= weight  of  condensing  water  in  barrel,  360  Ibs.; 
w=  weight  of  steam  and  water  from  steam-pipe; 
t  =  temperature  of  the  steam  at  the  gage  pressure  noted,  to 

be  found  in  steam  tables; 
ti  =  initial  temperature  of  condensing  water; 
i2  =  final  temperature  of  water  after  steam  is  condensed; 
1  =  total  latent  heat  of  steam  at  pressure  of  test  to  be  found 

in  steam  tables; 
k = water  equivalent  of  calorimeter, 


14 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


Barrus  Throttling  Calorimeter.— The  following  descrip- 
tion of  a  form  of  throttling  calorimeter  designed  by  Geo.  H.  Barrus 
of  Boston  will  be  found  in  Babcock  &  Wile  ox  Co.'s  publication 
"Steam": 


FIG.  3.— General  Arrangement  of  Barrus  Throttling  Calorimeter. 


FIG.  4. — Detail  of  Barrus  Throttling  Calorimeter. 

**  Steam  is  taken  from  a  ^-in.  pipe  provided  with  a  valve  and 
passes  through  two  f-in.  tees  situated  on  opposite  sides  of  a  f-in. 
flange  union.  A  thermometer  cup  or  well  is  screwed  into  each  of 
these  tees,  and  a  piece  of  sheet-iron  perforated  with  a  |-in.  hole 
in  the  center  is  inserted  between  the  flanges  and  made  tight  with 
rubber  or  asbestos  gaskets,  which  also  act  as  non-conductors  of 
heat.  For  convenience  a  union  is  placed  near  the  valve  as  shown, 
and  the  exhaust  steam  may  be  led  away  by  a  short  IJ-in.  pipe, 


THE  GENERATOR.  15 

shown  in  the  illustration  by  dotted  lines.  The  thermometer  wells 
are  filled  with  mercury  or  heavy  cylinder-oil,  and  the  whole  instru- 
ment from  the  steam-main  to  the  H-in.  pipe  is  well  covered  with 
hair  felt. 

"  Great  care  must  be  taken  that  the  J-in.  orifice  does  not  become 
choked  with  dirt,  and  that  no  leaks  occur,  especially  at  the  sheet- 
iron  disc,  also  that  the  exhaust-pipe  does  not  produce  any  back 
pressure  below  the  flange.  Place  a  thermometer  in  each  cup,  and, 
opening  the  ^-in.  valve  wide,  let  steam  flow  through  the  instru- 
ment for  10  or  15  minutes;  then  take  frequent  readings  on  the  two 
thermometers  and  the  boiler  gauge,  say  at  intervals  of  one  minute. 

"  The  throttling  calorimeter  depends  on  the  principle  that  dry 
steam  when  expanded  from  a  higher  or  lower  pressure  without 
doing  external  work  becomes  superheated,  the  amount  of  super- 
heat depending  on  the  two  pressures. 

"  If,  however,  some  moisture  be  present  in  the  steam,  this 
must  necessarily  be  first  evaporated  and  the  superheating  will  be 
proportionately  less.  The  limit  of  the  instrument  is  reached  when 
the  moisture  present  is  sufficient  to  prevent  any  superheating. 

"  Assuming  that  there  is  no  back  pressure  in  the  exhaust,  and 
that  there  is  no  loss  of  heat  in  passing  through  the  instrument, 
the  total  heat  in  the  mixture  of  steam  and  moisture  before  throt- 
tling, and  in  the  superheated  steam  after  throttling,  will  be  the 
same  and  will  be  expressed  by  the  equation 

ff-^r=  1146.6  +  0.480-212), 

in  which  x= percentage  of  moisture;  H=  total  heat  above  32°  in 
the  steam  at  boiler  pressure;  L  =  latent  heat  in  the  ste.am  at  boiler- 
pressure;  1146. 6  =  total  heat  in  the  steam  at  atmospheric  pressure; 
t  =  temperature  shown  by  lower  thermometer  of  calorimeter;  212  = 
temperature  of  dry  steam  at  atmospheric  pressure. 

"  Calibration. — Theoretically  the  boiler  pressure  is  indicated 
by  the  temperature  of  the  upper  thermometer,  but  owing  to  radia- 
tion, etc.,  it  is  usually  too  low,  and  it  is  better  to  use  the  readings 
of  the  boiler  gauge,  if  correct,  or,  better  still,  to  have  a  test-gauge 
connected  on  the  J-in.  pipe  supplying  the  calorimeter. 

"  If  the  instrument  be  well  covered,  and  there  is  as  little  radiat 
ing  surface  as  possible,  -the  above  assumption  that  there  is  no  loss 
of  heat  in  passing  through  the  instrument  may  be  nearly,  though 
never  quite,    correct.     On  the    other   hand  it  is  possible  to  be 


16  AMERICAN  GAS-ENGINEERING  PRACTICE. 

very  far  from  correct,  and;  to  eliminate  any  errors  of  this  kind, 
Mr.  Barrus  recommends  a  so-called  '  calibration '  for  dry  steam. 
This,  again,  involves  an  assumption  which  is  open  to  some  doubt, 
which  is  that  steam,  when  in  a  quiescent  state,  drops  all  its  mois- 
ture and  becomes  dry.  No  other  practical  method,  however,  has 
been  proposed,  and  this  is  therefore  the  only  method  used  at  the 
present  time.  Some  engineers,  however,  refuse  to  make  any 
calibration,  but  instead  make  an  assumed  allowance  for  error. 

"  To  make  the  calibration  close  the  boiler  stop-valve,  which 
must  be  on  the  steam-pipe  beyond  the  calorimeter  connection; 
keep  the  steam  pressure  exactly  the  same  as  the  average  pressure 
during  the  test  for  at  least  fifteen  minutes,  taking  readings  from 
the  two  thermometers  during  the  last  five  minutes.  The  upper 
thermometer  should  read  precisely  the  same  as  during  the  test, 
and  the  lower  thermometer  should  show  a  higher  temperature; 
this  reading  of  the  lower  thermometer  is  the  calibration  reading 
for  dry  steam,  which  we  will  call  T. 

"  Calculation  of  results,  allowing  for  radiation,  by  calibration 
method  is  made  by  this  formula: 


in  which  x= percentage  of  moisture;  T= calibration  reading  of 
lower  thermometer;  Z  =  test  reading  of  lower  thermometer;  L  = 
latent  heat  of  steam  at  boiler  pressure. 

"  The  method  of  taking  a  sample  of  steam  from  the  main  is 
of  the  greatest  importance,  and  more  erroneous  results  are  due 
to  improper  connections  than  to  any  other  cause.  The  sample 
should  be  taken  from  the  main  steam  current  of  the  steam  ascend- 
ing in  a  vertical  pipe.  Avoid  perforated  and  slotted  nipples  and 
use  only  a  plain,  open-end  nipple  projecting  far  enough  into  the 
steam-pipe  to  avoid  collecting  any  condensation  that  may  be  on 
the  sides  of  the  pipe.  Take  care  that  no  pockets  exist  in  the  steam- 
main  near  the  calorimeter  in  which  condensation  can  collect  and 
run  down  into  the  sampling-nipple.  Make  connections  as  short 
as  possible.  "  As  mentioned  above,  there  is  a  limit  in  the  range  of 
the  throttling  calorimeter  which  varies  from  2.88%  at  50  Ibs.  pres- 
sure to  7.17%  at  250  Ibs.  When  this  limit  is  reached  a  small  sepa- 
rator may  be  interposed  between  the  steam-main  and  the  cal- 
orimeter, which  will  take  out  the  excesses  of  moisture.  By  weigh- 
ing the  drip  from  the  separator  and  ascertaining  its  percentage 
of  the  steam  flowing  through,  and  adding  this  to  the  percentage 
of  moisture  in  the  steam,  the  total  moisture  may  be  ascertained. 


THE  GENERATOR.  17 

It  is  seldom,  however,  in  a  well-designed  boiler  that  any  but  a 
throttling  calorimeter  becomes  necessary." 

Generator  Details. — It  is  not  necessary  to  determine  the 
specific  gravity  of  steam  coal  as  a  method  of  checking  the  uni- 
formity of  the  supply.  The  difficulty  of  securing  a  fair  sample  of 
the  run,  and  the  inaccuracies  incident  to  the  determination,  have 
made  this  method  of  but  little  value,  it  being  entirely  inadequate 
as  compared  wifch  the  more  general  custom  of  a  complete  analysis. 
An  even  more  practicable  method  than  such  analysis,  perhaps,  is 
that  of  keeping  an  exact  and  careful  account  of  results  obtained. 

As  a  substitute  for  the  usual  steam-nozzle  under  the  grates  of 
the  generator,  an  ordinary  malleable  T  fitting  may  be  used,  the 
steam-connection  being  in  the  side  of  the  fitting.  This  has  the 
advantage  of  acting  in  a  small  way  as  a  steam-separator,  the 
incoming  steam  impinging  against  the  side  of  the  T  and  the  con- 
densation or  drip  falling  through  the  lower  opening. 

The  general  results  of  the  modern  water-gas  generator  (U.G.I, 
apparatus)  indicate  a  consumption  of  from  30  to  32  Ibs.  of  water 
per  1000  cu.  ft.  of  gas  made.  Of  this  steam  only  about  50%  is 
actually  converted  into  gas,  or,  in  other  words,  only  about  15  to 
16  pounds  of  steam  per  thousand  feet  of  gas  is  dissociated,  entail- 
ing a  loss  in  net  efficiency  of  from  2  to  3  Ibs.  of  boiler  fuel,  to  say 
nothing  of  the  generator  fuel  wasted  and  "  killed."  The  propor- 
tion of  steam  decomposed,  says  Mr.  Norris,  during  the  early  part 
of  the  run,  is  much  larger  than  during  the  last  few  minutes,  and 
this  seems  to  point  towards  desirability  of  shorter  runs,  and  pos- 
sibly a  more  closely  regulated  admission  of  steam,  instead  of  fol- 
lowing the  usual  custom  of  admitting  steam  at  a  constant  rate 
throughout  the  entire  run.  In  addition  to  this,  as  has  been  before 
mentioned,  the  make  of  CO2  is  in  inverse  ratio  to  the  steam  dis- 
sociated. The  matter  of  short  runs  may  be  carried  to  an  extreme, 
making  the  regulation  of  generator  heat  difficult  and  reducing  the 
gross  production  of  the  machine  per  hour  materially.  The  quan- 
tity of  steam  used  in  the  engine  operating  the  blower  of  a  water- 
gas  set  is  variously  estimated  at  from  15  to  30  Ibs.  per  1000  cu.  ft. 
per  hour. 

The  amount  of  water  necessary  for  boiler  evaporation,  steam 
for  exhausters,  fan-engines,  oil-pumps,  etc.,  will  average  about  5  to  6 
Ibs.  per  1000  cu.  ft.  of  gas  manufactured.  The  average  amount  of 
boiler  fuel  necessary  to  convert  this  water  into  steam  will  average, 
perhaps,  1.5  Ibs.  of  coal  per  boiler  per  horse-power  hour. 

The  boiler  installations  in  a  water-gas  plant  should  never  exceed 
the  minimum  of  2.5  h.p.  per  1000  cu.  ft.  of  make  per  hour,  3  h.p. 
being  a  safer  factor  for  installation.  In  small  works  there  should 
always  be  in  reserve  one  boiler;  in  large  works  the  proportion- 


18  AMERICAN  GAS-ENGINEERING  PRACTICE. 

ate  reserve  of  one  boiler  in  five  should  be  maintained.  A.  S. 
Miller  says  that  the  consumption  of  steam  in  his  experiments 
equalled  67.34  Ibs.  per  1000  cu.  ft.  of  gas  manufactured.  This  will 
not  allow  for  steam  used  in  heating. 

In  steam-piping  for  engines,  where  bends  are  used  the  fitting 
at  joints  should  be  done  with  a  slight  stress  upon  the  cold  pipe. 
No  actual  rule  for  this  can  be  stated  except  as  determined  prac- 
tically by  any  expert  fitter.  When  the  pipe  becomes  hot  this 
strain  is  removed  by  expansion  and  leaves  it  more  ready  to  receive 
the  vibration  to  which  it  is  subjected.  Good  fitting  with  the  best 
material  obtainable  is  invariably  economy  in  the  end.  Steel 
flanges  welded  to  the  pipe  and  pulled  up  with  intervening  copper 
gaskets  make  the  tightest  joint.  Where  high-pressure  steam  is  used 
and  the  work  can  be  accomplished  without  a  drop  of  pressure  of, 
-say,  4%,  it  is  good  practice  to  run  from  the  boiler  (if  near  at  hand) 
a  steam-pipe  of  one  or  two  sizes  smaller  than  the  inlet  or  throttle 
valve  of  the  engine.  This  pipe  should  be  increased  to  full  size 
within  a  few  feet  of  the  throttle,  which  serves  the  dual  purpose  of 
having  the  full  supply  of  steam  close  at  hand,  to  meet  the  admis- 
sion stroke  and  also  to  cushion  the  kick  or  recoil  of  the  steam  due 
to  the  closing  of  the  valve  at  the  point  of  cut-off. 

Generator  Operation. — A  sight-cock  is  of  unquestionable 
advantage  when  placed  on  the  coaling-valve  of  the  generator,  in 
that  it  may  enable  the  gas-maker  to  watch  the  condition  of  his 
fire  without  opening  the  valve.  Many  superintendents  use  this 
sight-cock  as  a  test  for  "  excess  steam  "  on  the  generator,  such 
being  denoted  by  moisture  on  the  inside  of  the  eye-glass  during  the 
run. 

In  letting  down  or  putting  out  of  operation  a  set,  the  best 
practice  dictates  that  the  generator  lid,  or  coaling-valve,  be  left 
closed.  The  clinkering-doors  are,  however,  left  slightly  ajar,  a 
slight  draught  should  be  left  on  the  carburetter  through  the  blast- 
valve  (the  blower  being  shut  down),  and  the  top  sight-cock  on  the 
carburetter  left  open,  as  is  also,  of  course,  the  stack-valve. on  the 
superheater. 

It  is  a  common  practice  on  machines  with  reversing  steam 
connections  to  make  every  third  run  a  down-run,  except  that  one 
preceding  and  the  one  succeeding  the  coaling  period,  when  the 
down-run  should  always  be  omitted. 

Generators  should  be  clinkered  and  thoroughly  cleaned  at  least 
twice  every  24  hours.  In  this  operation  the  machine  should  be 
let  down,  the  coaling-valve  or  lid  opened,  the  clinkering  and  ash 
doors  also  being  opened  or  removed ;  the  fire  should  then  be  barred 
down  thoroughly  and  all  lumps  of  clinker  and  ash  carefully  removed. 
This  clinker,  if  allowed  to  remain,  is  not  only  inert  and  wasteful 


THE  GENERATOR.  19 

of  heating  space,  but  it  prevents  the  blast  from  proper  circulation 
and  has  a  remarkable  condensing  effect  upon  the  steam.  It  tends 
to  chill  the  fire  and  prevents  diffusion  of  both  air  and  steam  through- 
out the  generator  area. 

For  the  elimination  of  carbon  deposits  on  the  checker  brick  of 
the  carburetter  and  superheater,  Mr.  R.  H.  Sterling  of  Watson- 
ville,  Cal.,  suggests  the  burning  of  zinc  in  the  generator,  a  process 
which  has  served  him  most  successfully. 

To  reduce  the  cost  of  what  would  otherwise  be  a  very  expen- 
sive process,  the  zinc  parts  of  old  dry-cell  batteries,  spent  elec- 
trodes, scrap  zinc,  etc.,  are  used;  such  being  obtainable  from  the 
telephone  and  telegraph  companies,  junk  yards,  tinners,  etc.,  at  a 
nominal  cost.  This  zinc  is  thrown  into  the  generators  with  the 
fuel  and  burned,  having  a  tendency  to  remove  the  carbon  deposits 
as  aforesaid. 

The  linings  of  a  water-gas  generator  should,  in  the  case  of  a 
good  quality  of  material  and  an  average  grade  of  coke  or  anthracite 
coal,  last  at  least  three  years;  the  period,  however,  is  apt  to  be 
somewhat  shorter  with  coke  than  coal,  by  reason  of  its  rapid 
variation  of  temperature  and  intensity  of  heat;  moreover,  should 
either  this  coke  or  coal  be  high  in  ash  or  have  a  marked  tendency 
to  clinker,  the  life  of  the  linings  may  be  reduced  to  two  years. 

The  life  of  these  linings  is  also  materially  affected  by  the  care 
of  handling,  heats  of  "  green  sets  "  should  of  course  be  brought  up 
slowly,  sets  should  not  be  "forced,"  etc.;  the  necessity  of  careful 
operating  conditions  being  intensified  in  the  case  of  the  checker 
brick,  which  under  the  use  of  average  quality  gas-oil  should  last 
"the  rise"  of  a  year,  while  other  conditions  of  operation  may 
reduce  their  service  to  half  that  period. 

It  is  the  belief  of  the  writer  that  the  most  disastrous  element 
in  the  operation  of  either  linings  or  checker  are  long  daily  "  stand- 
bys,"  wherein  the  temperatures  of  the  apparatus  have  time  to 
greatly  vary.  This  fact  will  also  be  observed  in  the  case  of  coal- 
gas  benches,  which  frequently  vary  in  life  from  5  years  to  3  years, 
according  to  the  nature  of  their  service. 

Generator  Fuels  Compared. — Anthracite  coal  contains  less 
ash  than  gas-coke  and  will,  therefore,  make  less  clinker.  Since 
it  is  much  denser  than  coke,  a  given  generator  volume  will  hold  a 
much  greater  weight  of  coal  fuel  and  it  will  neither  heat  up  nor 
lose  its  heat  as  rapidly  as  coke.  Therefore  when  coal  is  used 
longer  runs  and  blows  or  blasts  should  be  made,  as  this  increases 
the  make  or  gas  production  of  the  machine  per  hour  by  the  differ- 
ence in  time  required  for  the  opening  and  closing  of  valves  in  put- 
ting on  and  taking  off  runs  and  blows  on  the  apparatus;  this  time 
is  materially  increased  in  the  use  of  coke  by  the  fuel-charging 


20  AMERICAN  GAS-ENGINEERING  PRACTICE. 

period,  which  occurs  much  more  frequently  in  the  use  of  coke  than 
of  coal. 

As  an  advantage,  however,  on  the  side  of  coke,  it  presents  to 
the  action  of  the  blast  and  to  the  steam  a  much  larger  surface  than 
does  anthracite  coal,  owing  to  its  porous  nature.  The  irregular 
form  and  roughness  of  the  surface  of  the  individual  pieces  of  coke 
keep  the  fuel-bed  in  a  condition  favorable  to  the  general  and  inti- 
mate contact  of  both  blast  and  steam  with  the  carbon  of  the  fuel. 
The  heat  can  therefore  be  gotten  up  quickly,  and  the  gas  made  at 
a  rapid  rate  during  the  shorter  run  and,  with  quick  workmen,  the 
increase  of  time  required  for  handling  the  valves,  owing  to  the 
shortness  of  the  blow  and  run,  is  not  of  great  importance.  It  is 
necessary  when  using  gas-coke  to  be  very  careful  not  to  prolong 
either  the  blows  or  runs,  for,  owing  to  the  rapidity  with  which  the 
coke  is  consumed,  any  over-blowing  largely  increases  the  fuel 
account,  while  any  extra  length  of  run  increases  the  amount  of 
carbonic  acid  in  the  gas  very  rapidly,  since  the  fire  cools  off  quickly. 

It  has  been  the  experience  of  the  writer  that  coke  is  most  advan- 
tageous when  used  in  sets  too  small  to  have  reverse  steam  connec- 
tions, as  the  coke  revivifies  more  rapidly  and  presents  a  larger  and 
fresher  surface  to  the  action  of  the  steam.  It  is  also  less  apt  to 
form  into  pits  and  blast-holes,  through  which  the  steam  in  the 
generator  may  pass  undecomposed. 

In  general  it  is  probable  that  fair  results  as  to  the  quantity  of 
fuel  per  1000  cu.  ft.  of  gas  manufactured  and  the  quality  of  the 
gas  made  can  be  secured  more  readily  from  coal  than  from  gas- 
coke,  especially  when  large  machines  are  used. 

Furnace-  or  oven-coke,  unless  it  is  made  from  carefully  washed 
coal,  or  coal  that  is  originally  free  from  ash,  is  apt  to  contain  more 
ash  than  gas-coke  and  to  give  trouble  from  clinker.  It  does  not 
possess  the  density  of  anthracite  coal,  nor  is  it  as  porous  as  gas- 
coke.  The  48-hour  coke  makes  a  much  better  generator  fuel  than 
the  72-hour  hard  coke.  Opinions  as  to  the  relative  values  of  these 
cokes,  however,  differ.  There  is  much  more  to  do  with  the  proper 
handling  of  these  fuels  than  with  the  little  differences  which  exist 
between  them,  for  even  slight  differences  in  the  price  or  local  con- 
ditions are  sufficient  to  turn  the  advantage  in  favor  of  one  or  the 
other. 

When  anthracite  coal  is  used,  the  trustees  of  the  Educational 
Class  of  the  American  Gaslight  Association  suggest  as  follows: 
"  The  size  of  anthracite  that  is  usually  considered  available  for 
generator  fuel  is  either  '  steamboat/  consisting  of  pieces  that  will 
pass  through  a  screen  with  4-  to  7-in.  mesh  (the  smaller  pieces 
having  been  screened  out) ;  or  '  broken/  consisting  of  pieces  that 
would  pass  through  a  4-in.-square  mesh  and  over  a  2f-in.  mesh; 


THE  GENERATOR.  21 

or  '  egg/  consisting  of  pieces  that  would  pass  through  a  2J-  to  2f- 
in.  mesh  and  over  a  IJ-in.  mesh.  Of  these  sizes  that  known  as 
'  broken  '  has  been  found  to  give  the  best  results  for  generator  use, 
though  in  many  large  generators  (those  over  8  ft.  in  diameter)  steam- 
boat size  would  be  better.  The  advantages  possessed  by  '  broken  ' 
coal  are  that  the  lumps  are  sufficiently  large  to  maintain  the  bulk 
of  the  fire  in  an  open  state,  which  affords  the  ready  passage  to  the 
air  in  blasting  and  the  steam  when  making  gas,  and  yet  are  small 
enough  to  present  a  large  surface  of  carbon  to  be  acted  upon  by 
the  oxygen,  and  it  is  thus  possible  to  secure  the  proper  combina- 
tion of  the  greater  portion  of  both  oxygen  and  carbon  in  each  case. 
Smaller  coal  affords  a  larger  coal  surface,  but  at  the  same  time 
forms  a  large  compact  mass  in  the  center  of  the  generator  through 
which  the  air  and  steam  cannot  pass  readily.  They  therefore  pass 
only  through  that  portion  of  the  area  of  the  generator  which  lies 
between  the  outside  walls  and  this  compact  mass  in  the  center. 
The  larger-sized  coal  affords  a  freer  fire  with  much  less  total  sur- 
face, and  is  also  much  harder  to  handle. 

"  In  his  paper  on  the  subject,  C.  R.  Collins  states  that  the  inac- 
tive portion  of  the  fire  which  is  due  to  the  compacting  of  the  coal 
in  the  center  of  the  generator,  where  the  lumps  can  fit  each  other 
more  perfectly  than  they  can  in  the  space  next  to  the  walls,  "  varies 
with  the  diameter  (of  the  generator)  and  with  the  size  of  the  coal; 
thus  in  a  particular  generator  '  egg '  coal  renders  about  30%  of 
the  fire  partially  inactive,  the  bulk  of  the  work  being  done  in  the 
outer  parts  representing  70%  of  the  fuel ;  in  the  same  way  '  broken  ' 
coal  affects  about  15%  of  the  fuel-bed,  while  '  steamboat '  coal 
leaves  a  practically  free  fire.  .  .  .  '  Steamboat '  coal  presents  ap- 
proximately 7  sq.  ft.  of  surface  for  each  cubic  foot  of  generator 
space.  '  Broken  '  coal,  10  sq.  ft.  of  surface  per  cubic  foot  of  space; 
and  '  egg  '  coal,  22  sq.  ft.  of  surface  per  cubic  foot  of  space.  These 
figures  are  for  selected  coal  of  the  standard  size  in  each  case.  In 
practice  the  '  steamboat '  coal  will  have  some  broken  coal  in  it,  and 
the  '  broken '  some  '  egg/  and  so  on,  and  the  presence  of  this 
smaller  coal  will  increase  the  size  of  the  inactive  portion  of  the 
fire  as  well  as  the  amount  of  average  surface  presented  to  the 
steam.  It  is  important,  no  matter  what  size  is  being  used,  that 
the  smaller  pieces  and  slack  should  be  screened  out  and  not  used  in 
the  generator,  the  coal  used  being  kept  as  nearly  as  possible  to  the 
size  of  the  selected  standard." 

What  has  been  said  with  regard  to  anthracite  coal  also  applies 
to  coke.  When  oven  coke  is  used  the  large  pieces  in  which  it 
comes  from  the  oven  should  be  broken  up  to  a  size  corresponding 
to  "  broken  "  coal  (i,e.,  pieces  which  pass  through  a  4-in.  mesh  and 
over  a  2j-in.  mesh),  before  the  coke  is  charged  into  the  generator. 


22  AMERICAN  GAS-ENGINEERING  PRACTICE. 

On  the  other  hand  the  coke  after  being  broken  should  be  picked 
up  with  a  fork  in  such  a  way  as  to  leave  behind  the  small  pieces 
and  dust,  which  should  not  be  used  in  the  generator.  When  coke 
is  made  in  coal-gas  retorts  it  does  not  require  any  breaking,  but 
must  be  picked  up  with  a  fork  to  avoid  any  presence  of  dust  and 
"  breeze."  It  must  be  remembered  that  a  fork  can  be  used  in  such 
a  way  as  to  pick  up  almost  as  much  as  a  shovel,  and  that  when 
loading  coke  which  is  to  be  taken  to  the  generator  the  fork  is  to 
be  well  shaken  while  the  coke  is  on  it,  for  the  purpose  of  dislodging 
the  dust  and  small  pieces  that  the  larger  pieces  may  have  picked  up. 

It  is  the  author's  opinion  that  the  greatest  field  in  the  future 
economical  production  of  water-gas  lies  along  the  development  of 
superheated  steam. 

As  yet  little  seems  to  be  known  of  this  subject,  the  properties 
of  the  steam,  its  line  of  expansion,  or  its  temperatures.  But  when 
these  properties  are  thoroughly  understood  and  adapted  to  water- 
gas  manufacture,  it  is  certain  that  the  result  will  not  only  reduce 
the  cost  of  manufacture  by  reason  of  the  saving  of  generator  fuel 
effected,  but  it  will  likely  result  in  the  manufacture  of  a  more 
permanent  and  better  gas,  free  from  aqueous  vapor  or  excess  con- 
densation, together  with  the  faults  invariably  attendant  upon  these 
features. 

Spontaneous  combustion  in  coal  seems  to  be  favored  by  any 
or  all  of  four  conditions:  first,  the  piling  of  the  coal  to  any  great 
depth  (say  12  feet  or  more),  so  that  the  weight  of  the  coal  brings 
considerable  pressure  to  bear  upon  the  lower  parts  of  the  pile 
(same  condition  holds  good  with  tight  bins);  second,  finely 
broken  or  run-of-the-mine  coal;  third,  a  high  percentage  of  sul- 
phur or  iron  pyrites;  and  fourth,  moist  and  freshly  mined  coal  are 
especially  susceptible. 

Carbon  Dioxide. — This  gas  is  due  to  incomplete  reduction 
of  the  CO2  first  formed  to  CO  by  the  upper  layers  of  incandescent 
carbon,  or  to  that  remaining  in  the  apparatus  after  blasting.  As 
the  temperature  of  the  fuel  falls  the  proportion  increases,  as  shown 
in  the  following  table: 


CARBON  DIOXIDE  IN  WATER-GAS  DURING  A  FIVE-MINUTE  RUN. 


Minutes. 
End  of 
1  

Butterfield. 
Per  Cent. 
0.3 

O'Connor. 
Per  Cent. 

0.5 

2  

0.6 

1.5 

3  

1.4 

4.1 

4  

2.6 

6  2 

5.. 

.  4.2 

7.9 

THE  GENERATOR.  23 

The  proportion  of  CO2  is  seen  to  increase  with  the  length  run. 
CO2  in  water-gas  varies  under  normal  conditions  from  1  to 
.5  per  cent,  but  only  3  per  cent  should  be  permitted  in  good  practice. 
O'Connor's  analysis  of  American  water-gas  is  as  follows: 

Constituents.  Per  Cent. 

CO2 3.5 

CO 43.4 

H 51.8 

N 1.3 

Water-gas  of  itself  has  practically  no  illuminating  power, 
having  a  faint  bluish  color.  ^ 

When  air  is  forced  through  red-hot  coke,  1  Ib.  of  carbon,  burn- 
ing to  CO,  liberates  4500  B.t.u.;  but  if  burned  to  CO2  it  liberates 
14,500  B.t.u.  If  there  be  sufficient  quantity  of  carbon  for  the 
CO2  to  pass  through,  it  is  decomposed  with  the  absorption  of 
10,000  B.t.u.  Since  1  Ib.  of  C  requires  1.25  Ibs.  of  O  to  form  CO, 
it  produces  2.25  Ibs.  of  CO.  The  quantity  of  air  containing  1.25 
Ibs.  of  O  would  contain  4.5  Ibs.  of  N. 

The  minimum  temperature  for  the  formation  of  pure  water-gas 
is  1800°  F.  A  lesser  heat  would  mean  imperfect  combination  of 
the  C  and  O  and  result  in  the  production  of  CO2. 

Too  little  attention  is  generally  given  to  the  maintenance  of 
uniform  heats  in  the  generator  and  to  the  keeping  down  of  the  per- 
centage of  CO2.  Some  idea  as  to  the  detrimental  effect  of  this 
compound  will  be  given  by  the  following  approximate  table: 

EFFECT   OF   CARBON    DIOXIDE    ON   THE   CANDLE   POWER   OF   GAS. 


2.5%  CO2  causes  a  loss 

of      9%  in  candle 

power. 

5% 

i  t 

1  1 

n 

i  ( 

"     20%  " 

i  t 

tt 

10% 

tt 

ft 

a 

(  t 

"     40%  " 

tt 

tt 

20% 

tt 

it 

it 

tt 

"     75%" 

11 

tl 

30% 

tt 

1  1 

" 

tt 

"     90%" 

It 

tt 

58% 

1  1 

1  1 

" 

1  1 

"  100%" 

tt 

tt 

Carbon  Dioxide  Analysis:  Description. — "As  the  amount  of 
carbonic  acid  in  the  water-gas  depends  largely  on  whether  the 
apparatus  is  properly  handled  or  not,  and  as  an  excess  of  carbonic 
acid  very  seriously  affects  the  illuminating  power  of  the  gas,  it  is 
convenient  to  have  an  apparatus  by  which  the  percentage  of  car- 
bonic acid  can  be  quickly  and  easily  ascertained  at  any  tune.  The 
fact  that  carbonic  acid  is  readily  absorbed  by  caustic  potash  is 
taken  advantage  of  as  follows:  A  solution  of  about  1  part  by 


24 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


weight  of  potash  to  3  parts  by  weight  of  water  is  prepared.  The 
absorption  and  measuring  apparatus  shown  in  Fig.  5  is  placed  in 
a  convenient  position  and  the  absorption  pipette  is  filled  with  the 
potash  solution.  This  pipette  is  best  filled  when  made  with  small 
rolls  of  iron-wire  gauze,  as  the  absorbing  surface  is  thus  much 
increased.  One  branch  of  the  three-way  cock  at  the  top  of  the 
measuring  burette  is  connected  by  the  capillary  glass  tube  with 
the  pipette.  The  joints  are  made  of  rubber  tubing.  The  measuring- 
burette  is  made  to  hold  100  cubic  centimeters,  and  is  graduated  to 
read  to  0.2  centimeter.  A  large  glass  tube,  stopped  at  each  end 


[FiG.  5. — Carbonic-acid  Gas  Apparatus. 

with  rubber  plugs,  is  placed  outside  the  burette.  The  space  between 
the  burette  and  the  outside  is  filled  with  water,  forming  a  water- 
jacket,  which  maintains  the  gas  at  an  even  temperature  when  in 
the  burette*.  A  leveling-tube  is  connected  by  a  long  rubber  tube 
with  the  bottom  of  the  burette.  This  bulb  is  filled  with  water, 
preferably  distilled,  which  has  been  saturated  with  gas  by  allowing 
a  small  stream  of  gas  to  bubble  through  it. 

Operation. — "  Open  lower  stop-cock  1  and  turn  three-way  stop- 
cock (a)  so  that  the  burette  is  open  to  pipette;  then,  by  lowering 
the  level-bulb  6,  draw  the  potash  solution  up  the  capillary  tube  to 
the  point  e,  just  before  the  capillary  turns  down,  and  close  the  stop- 
cock a.  Leaving  lower  stop-cock  open,  turn  stop-cock  a  until  the 


THE  GENERATOR.  25 

capillary  tube  c  is  open  to  the  burette,  and  then,  by  raising  the 
level  bulb  6,  fill  burette  completely  full  of  water.  Close  stop-cock 
1.  Now  attach  the  rubber  tube  to  the  gas  supply  and  allow  gas  to 
flow  through  the  tube  for  a  moment  to  displace  air;  then,  with  gas 
still  flowing,  attach  free  end  of  tube  to  capillary  c.  Open  lower 
stop-cock  1,  and  then  close  stop-cock  a  and  detach  rubber  tube. 
After  3  minutes  bring  the  level  of  the  liquid  in  the  burette  exactly 
to  100  c.c.  merely  by  raising  or  lowering  the  level-bulb  and  close 
lower  stop-cook  1.  Open  stop-cock  a  to  capillary  c  for  a  moment 
hi  order  to  allow  surplus  gas  to  escape.  There  will  be  exactly 
100  c.c.  of  gas  in  the  burette,  measured  under  atmospheric  pres- 
sure. Now  open  stop-cock  a  to  the  pipette  and  force  gas  over  to 
the  pipette  by  raising  the  level-bulb,  draw  gas  back  into  the  burette 
immediately,  letting  the  potash  solution  follow  up  the  capillary 
tube  to  the  point  e  as  before,  and  close  stop-cock  a.  After  3  min- 
utes, by  raising  or  lowering  the  level-bulb  b,  bring  the  water  in 
burette  and  level-tube  to  the  same  level  and  close  stop-cock  1.  Note 
the  point  at  which  the  water  now  stands  in  the  burette,  and  the 
difference  between  this  reading  and  the  original  amount  taken  will 
be  the  carbonic -acid  gas  absorbed. 

"The  glass  stop-cocks  of  the  apparatus  should  be  kept  greased 
with  glycerine,  as  otherwise  they  may  stick  and  break  when  an 
attempt  is  made  to  turn  them.  A  glass  cock  that  has  stuck  can 
usually  be  loosened  by  the  application  of  a  cloth  wet  with  hot 
water.  In  order  to  prevent  the  absorption  of  carbonic  acid  from 
the  atmosphere,  the  open  ends  of  both  level-bulb  and  pipette  should 
be  plugged  when  the  apparatus  is  not  in  use.  Where  unpurified  gas 
is  to  be  tested,  the  sulphureted  hydrogen  should  be  removed  by 
passing  the  gas  through  a  small  oxide  purifier  before  it  is  drawn 
into  the  burette.  The  solution  of  caustic  potash  in  the  pipette  will 
last  five  or  six  months  before  it  must  be  removed.  This  method 
of  absorption  is  the  base  of  all  the  usual  forms  of  gas  analysis, 
different  chemicals  being  used  to  replace  the  caustic  pot.ash  and 
absorb  the  different  components  of  the  gas  to  be  analyzed." 

Generator  Lining. — There  should  be  a  double  lining  in  the 
generator,  for  that  portion  extending  from  just  below  the  level  of 
the  grate-bars  to  a  point,  say,  5  ft.  above  these  bars,  which  will  be 
found  most  economical,  for  the  reason  that  on  this  section  is  the 
greatest  wear  and  tear,  both  from  heat  and  clinkering,  and  this 
section  can  be  renewed  when  necessary  without  disturbing  the 
remainder  of  the  lining. 

The  rest  of  the  lining  may  be  made  of  single  courses  of  blocks 
having  the  desired  thickness,  which  is  desirable,  inasmuch  as  these 
courses  require  no  support  when  the  inner  lining  is  renewed  under- 
neath. Inasmuch  as  the  wear  of  this  last-named  section  is  incon- 


26  AMERICAN  GAS-ENGINEERING  PRACTICE. 

siderable,  some  saving  in  time  and  labor  is  effected  by  using  the 
full-depth  blocks. 

Rapid  degeneration  of  generator  linings  usually  indicates  either 
excessive  blast  pressure,  too  lengthy  blasts,  or  an  insufficiency  of 
blast.  In  the  latter  case  the  blast  pressure  is  not  sufficient  in  its 
velocity  to  carry  the  products  of  primary  combustion  over  into 
the  other  retorts,  where  secondary  combustion  of  the  blast  gases 
should  take  place.  Hence  both  primary  and  secondary  combustion 
take  place  in  the  generator  alone. 

Repairing  Cements. — It  is  occasionally  necessary  to  patch  the 
fire-brick  in  the  generator  around  the  mouth  or  throughout  the 
lining,  and  for  this  a  compound  of  salt,  sal-ammoniac,  fire-clay,  and 
finely  powdered  fire-brick  is  a  good  cement,  as  is  also  a  composi- 
tion of  iron  filings  100  parts,  fire-clay  50  parts,  common  salt  10 
parts,  and  quartz  sand  or  pounded  fire-brick  20  parts.  For  attach- 
ing iron  and  stone  or  cement,  a  good  composition  is  fine  iron  filings 
10  parts,  plaster  of  Paris  10  parts,  sal-ammoniac  ^  part.  Fire- 
proof cement  for  iron  pipes  consists  of  wrought-iron  filings  45  parts, 
fire-clay  20  parts,  brick-clay  15  parts,  common  salt  8  parts.  As  a 
cement  for  filling  in  faults  in  iron  castings:  Iron  filings  free  from  rust 
10  parts,  sulphur  J  part,  sal-ammoniac  0.8  part,  mixed  with  water  to 
a  thick  paste  and  rammed  into  the  cavity.  The  part  to  be  treated 
should  be  previously  wiped  with  ammonia  to  free  it  from  grease. 
The  old  cement  commonly  used  for  joining  retorts  to  mouthpieces 
was  |  part  by  weight  of  fire-clay,  J  part  by  weight  of  iron  borings, 
mixed  with  ammonia  water. 

It  is  well  to  have  on  hand  for  emergencies  a  can  of  Tucker's 
cement.  This  cement  is  of  especial  use  in  making  temporary 
patches  on  blast-pipes,  gas-pipes,  valves,  etc.,  it  being  used  to 
advantage  when  wrapped  with  strong  muslin.  It  is  peculiarly  good 
in  temporarily  repairing  reversing-valves  between  the  generator 
and  carburetter  of  the  apparatus,  which  are  invariably  a  subject 
for  the  "  first  aid  to  the  injured,"  as  they  are  but  rarely  sufficiently 
water-jacketed. 

Blast.— Under  date  of  December  21,  1903,  D.  J.  Collins  said 
with  regard  to  the  blast  pressure  to  be  maintained  in  the  generator 
of  water-gas  sets:  "With  the  use  of  anthracite  coal  as  generator  fuel 
you  should  maintain  a  blast  pressure  under  the  generator  equal  to 
a  water  volume  of  15  in.  to  18  in.,  and  with  coke  from  12  in.  to  15 
in.  The  same  pressure  applies  to  all  sizes  of  apparatus.  The 
lower  pressure  with  coke  is  made  necessary  because  the  coke  is  so 
much  lighter  and  has  so  many  more  open  spaces  in  it  that  the 
blast  pressure  should  correspond  with  the  conditions  met." 

The  blast  on  both  generator  and  carburetter  should  be  con- 
stant in  its  pressure,  and  the  blast  line  should  be  thoroughly  ven- 


THE  GENERATOR. 


27 


tilated.  This  is  necessary  to  prevent  the  accumulation  of  dust, 
oil,  or  gas  in  the  blast  line  during  the  run,  or  in  the  pockets  of  the 
valves  immediately  connecting  the  machines,  and  which  would 
occasion  an  explosion  at  the  opening  of  the  valves  and  starting  up 
of  the  blast.  This  is  especially  needful  in  the  instance  of  machines 
having  reverse  steam  connections. 

Safety  Devices. — All  en%)loyees  about  the  works  should  be 
taught  the  location  of  all  valves,  steam,  water,  and  fas,  which 
should  be  labeled  as  to  direction  of  rotation,  and  should  be  espe- 
cially drilled  in  the  routine  of  their  duty  in  case  of  fire.  There 
should  be  near  the  generator  and  at  convenient  points  about  the 
works  (especially  in  the  purifying  room)  standard  2^-inch  water- 
outlets,  with  suitable  fire-hose  attached  and  neatly  coiled  on  racks 
ready  for  instant  use.  This  hose  should  preferably  be  linen  and 
unlined,  inasmuch  as  lined  hose,  especially  rubber,  is  damaged  and 
of  short  life  by  reason  of  the  heat  about  the  works. 

One  of  the  most  frequent  occasions  for  delay  and  shut-down  in 
water-gas  manufacture  is  due  to  explosion  in  the  blast-pipe  or  of 
difficulties  with  the  blower.  It  is  strongly  advisable  to  have 
inserted  in  each  line  of  blast-pipe  a  T  equal  in  diameter  to  the 
main  line.  On  this  T  should  be  a  cap  fitted  into  the  T  and  wrapped 


,1-A 

\  - 

«*T 

<#* 

rV 

V 

g 

AC/fi. 

-p 

~nn  h 

BLAST  PIPES. 
FIG.  6. — Safety  Blow-off  Blast-pipe. 

with  some  fabric  such  as  tire-tape  or  electric  insulating  tape.  This 
joint  should  be  made  to  withstand  a  pressure  of  not  more  than  one 
pound,  or  27  inches  of  water,  and  is  designed  in  case  of  an  explo- 
sion to  act  as  a  safety-valve  upon  the  blast  line. 

Fire=brick. — The  principal  precaution  to  be  taken  in  laying 
fire-brick  or  fire-clay  blocks  is  that  the  bricks  or  blocks  should  be 
thoroughly  wet  just  before  they  are  laid  in  place,  and  that  each 
brick  or  block  should  be  rubbed  into  place  in  such  a  way  as  to 
bring  its  faces  in  contact  with  the  faces  of  adjacent  brick  or  block 
in  the  wall,  the  joints  being  made  as  thin  as  possible,  and  at  the 


28  AMERICAN  GAS-ENGINEERING  PRACTICE. 

same  time  to  have  the  fire-clay  cement  or  mortar  fill  all  the  inter- 
stices, so  as  to  give  a  uniform  bearing  over  the  whole  surface.  This 
is  especially  important  in  the  case  of  arches,  which  should  be  laid 
as  nearly  as  possible  with  the  blocks  face  on  face.  Small  bricks 
and  blocks  can  be  wet  by  being  dipped  in  water.  The  surfaces  of 
large  blocks  should  be  wet  by  having  water  poured  on  them  with 
a  hose.  The  portion  of  the  work  previously  laid,  and  upon  which 
the  wet  bricks  or  blocks  are  to  be  placed,  should  also  be  wet. 

To  secure  thinness  of  joints  those  surfaces  of  the  blocks  which 
come  together  should  be  smooth,  plane  surfaces,  being  dressed  to 
this  condition  if  they  do  not  originally  possess  it,  and  the  fire-clay 
mortar  should  be  mixed  thin  rather  than  stiff,  care  being  taken 
that  it  is  not  so  liquid  as  to  run  out  of  the  joint,  nor  so  stiff  that 
any  excess  will  not  be  squeezed  out  when  the  joint  is  worked  into 
place.  If  the  joints  are  not  made  thin  the  fire-clay  will  soften  and 
run  when  subjected  to  extreme  heat,  or  it  will  shrink  under  the 
action  of  heat  and  cause  the  upper  portion  of  the  brickwork  to 
settle. 

When  it  is  necessary  to  cut  bricks  or  blocks,  the  cut  or  broken 
section  should  never  be  exposed  to  the  direct  action  of  the  fire,  the 
face  so  exposed  being  always  the  one  uncut  or  unbroken. 

The  qualities  desired  in  fire-bricks  or  blocks  are  infusibility, 
strength,  regularity  of  shape,  uniformity  of  composition  and  facil- 
ity of  cutting,  and  the  test  to  be  applied  to  a  fire-brick  should  be 
such  as  would  determine  to  what  extent  it  possesses  these  qualities. 

An  excellent  test  for  the  fire-resisting  qualities  of  fire-brick  is 
to  throw  a  brick  into  the  generator  along  with  the  coal  or  coke 
and  allow  it  to  pass  through,  taking  it  out  with  the  generator 
screenings.  Any  tendency  to  fuse  or  crumble  will  then  be  indi- 
cated by  the  condition  of  this  sample. 

The  degree  of  infusibility  can  be  determined  to  a  certain  extent 
by  an  analysis  of  the  material  of  which  the  brick  is  composed .  If  this 
analysis  shows  the  presence  of  about  60%  of  silica,  less  than  6%  of 
sequioxide  of  iron,  and  not  more  than  2%  to  3%  as  the  total  of 
lime,  magnesia,  and  hydrates  of  potassium  and  sodium,  the  brick 
probably  possesses  a  high  degree  of  infusibility.  If  the  analysis 
indicates  more  than  6%  of  sesquioxide  of  iron,  or  more  than  2%  to 
3%  of  lime,  magnesia,  etc.,  the  brick  should  be  rejected;  but 
exposure  of  the  bricks  to  the  action  of  heat  under  the  conditions 
to  which  it  will  be  subjected  when  used,  furnishes  the  best  test  of 
fusibility.  In  coal-gas  works  it  can  be  made  by  placing  the  brick 
in  the  combustion  chamber  of  the  generative  bench.  If  when  the 
brick  is  removed,  after  being  exposed  for  a  week  to  the  heat  of  the 
chamber,  the  edges  and  corners  are  found  to  be  sharp  and  the  sur- 
faces show  no  signs  of  incipient  fusion,  the  brick  may  be  passed 


THE  GENERATOR.  29 

as  a  ili'st-rate  quality  in  respect  to  infusibility.  In  water-gas  plants 
the  space  at  the  bottom  of  the  superheater  in  which  the  secondary 
combustion  occurs  furnishes  a  good  place  for  the  test,  or  the  pas- 
sage of  a  sample  brick  through  the  generator  together  with  the 
fuel. 

If  the  material  of  which  the  brick  is  made  is  well  compressed 
during  manufacture,  and  the  brick  is  hard-burned,  there  is  little 
question  as  to  its  strength  when  cold;  any  defect  in  material  or 
manufacture  is  indicated  by  crumbling  or  fusing.  The  degree  to 
which  compression  has  been  carried  is  indicated  by  the  weight  of 
the  brick.  A  fire-brick  of  regulation  size,  9x4.5X2f  inches,  should 
weigh  in  the  neighborhood  of  7.25  to  7.5  Ibs.  A  well-burned  brick 
should  have  a  reddish  tinge.  A  well-compressed  and  well-burned 
brick  should  give  a  ringing  sound  when  struck  with  a  hammer. 
It  is  especially  necessary  that  bricks  in  the  lining  of  retort-benches 
and  water-gas  generators  should  be  hard,  since  they  are  subjected 
to  a  great  deal  of  abrasions  from  the  fuel  and  the  clinkering-bar, 
so  that  to  this  work  hardness  and  strength  are  really  of  as  much 
importance  as  infusibility.  In  the  combustion  chamber,  as  in  the 
carburetter  and  superheater,  infusibility  is  the  more  important 
quality,  since  the  material  used  is  not  exposed  to  any  wear  and 
tear  except  that  arising  from  the  effects  of  the  heat,  and  it  may 
thus  frequently  happen  that  the  same  brick  is  not  suitable  for  use 
both  in  the  furnace  or  combustion  chamber  and  in  the  two  other 
chambers.  An  examination  of  the  exterior  of  the  brick  is  all  that 
is  necessary  to  determine  whether  or  not  it  possesses  regularity  of 
shape. 

Uniformity  of  composition  can  be  ascertained  by  breaking  the 
brick  and  examining  the  surfaces  of  the  fracture.  This  should 
present  a  compact  and  uniform  appearance,  though  not  necessarily 
a  close  and  fine  texture.  In  fact  some  authorities  prefer  a  coarse 
texture,  as  possessing  greater  infusibility.  Uniformity  of  composi- 
tion is  also  indicated  by  the  giving  out  of  a  clear  ringing  sound 
when  the  brick  is  struck  a  sharp  blow  with  a  hammer  or  trowel 
edge. 

Facility  of  cutting  is  important  only  as  reducing  the  cost  of 
labor  and  the  amount  of  waste  during  the  operation  of  laying  the 
brick,  and,  while  desirable  if  it  can  be  secured  without  sacrificing 
the  more  important  qualities,  cannot  be  considered  as  equivalent 
to  any  of  the  other  specified  qualities.  (The  above  information  is 
credited  to  the  trustees  of  the  gas  educational  class  of  the  American 
Gaslight  Association.) 

It  will  be  observed  in  the  study  of  fire-clays  (clays  having  a 
fusing-point  above  2700°)  that  the  coarser-grained  fire-brick  stand 
heat  better  than  the  finer  texture,  although  they  stand  less  well 


30  AMERICAN  GAS-ENGINEERING  PRACTICE. 

the  action  of  molten  metal.  In  their  order  they  have  been  classed 
as: 

No.  1.  Highly  refractory: 
a.  Flint  fire-clay; 
6.  Plastic  fire-clay. 
No.  2.  Moderately  refractory: 

a.  No.  2  "A  "  fire-clay; 

b.  Stoneware  clay; 

c.  Sewer-pipe  clay. 

The  method  of  manufacturing  fire-brick,  as  well  as  the  material 
of  which  they  are  made,  has  undoubtedly  much  to  do  with  their 
degree  of  excellence.  For  example:  All  things  being  equal,  the 
heat  conductivity  of  the  brick  would  vary  in  accordance  with  the 
pressure  which  was  applied  to  it  during  its  manufacture,  the  air 
spaces  between  its  particles,  or  the  porosity  of  the  brick,  decreas- 
ing its  conductivity. 

The  size  of  a  water-gas  generator  is  determined  by  most  engi- 
neers by  an  allowance  of  one  square  foot  of  grate  surface  for  each 
30,000  cu.  ft.  of  gas  made  in  24  hours;  the  fuel-bed  to  be  at  least 
8  to  9  ft.  deep. 

The  data  given  by  Alfred  Wolff  of  New  York  City  are  very 
often  used  for  computing  the  amount  of  heat  passing  through  fire- 
brick walls.  A  gives  the  thickness  of  the  wall  in  inches,  and  B 
gives  the  corresponding  number  of  B  passing  through  the  walls 
per  square  foot  of  area  per  hour  for  each  degree  difference  of  tem- 
perature (Fahrenheit)  between  the  two  sides: 

A 44      8       12      16      18     20     24     28     32      36     40 

B 0.43  0.37  0.32  0.28  0.26  0.25  0.24  0.22  0.21  0.18  0.18 

Hornby  says,  under  Analyses  of  Fire-brick  and  Clay,  pp.  194 
to  199:  A  refractory  fire-clay  will  contain  nearly  pure  hydrated 
silicate  of  alumina.  The  more  alumina  there  is  in  proportion  to 
the  silica  the  more  infusible  will  be  the  clay.  The  composition  of 
different  fire-clays  necessarily  varies,  however;  they  contain: 

Silica 59  to  96  per  cent. 

Alumina 2  to  36   "      " 

Oxide  of  iron 2  to    5   "      " 

and  a  very  small  percentage  of  lime,  magnesia,  potash,  and  soda. 
The  fire-resisting  properties  of  the  clay  depend  chiefly  upon  the 
relative  proportion  of  these  constituents.  If  oxide  of  iron  or 
alkalies  are  present  in  large  proportion  they  act  as  a  flux  and  result 
in  fusion.  The  clay  is  then  no  longer  refractory. 


THE  GENERATOR.  31 

Fire=clay  Analysis.— The  following  is  the  method  of  analysis: 
The  quantity  of  the  substance  (either  fire-clay  or  fire-brick)  is 
reduced  to  an  impalpable  powder  in  an  agate  mortar  and  placed  in 
a  stoppered  weighing-tube.  About  2  grams  of  this  sample  are 
dried  in  a  platinum  crucible  or  dish  at  a  temperature  of  about  100° 
C.  (212°  F.)  until  the  weight  is  constant;  the  loss  in  weight  gives 
the  moisture.  In  the  case  of  fire-clay  it  is  then  ignited,  at  first 
gently  and  then  strongly  and  for  a  tolerably  long  time.  The  loss 
of  weight  corresponds  to  the  water  in  combination  together  with 
the  organic  and  volatile  constituents  of  the  clay,  if  such  are 
present. 

Then  1.5  grams  of  the  powdered  sample  are  weighed  accurately 
into  a  platinum  crucible  and  about  four  times  this  weight  added  of 
a  fusion  mixture,  consisting  of  sodium  and  potassium  carbonates. 
The  whole  is  intimately  mixed  by  means  of  a  smooth,  rounded, 
glass  rod.  It  will  be  found  convenient  to  add  the  fusion  mixture  by 
small  portions  at  a  time,  since  in  this  way  a  more  thorough  mix- 
ture is  obtained.  The  mixture  should  only  half  fill  the  crucible. 

The  lid  is  then  placed  on  the  crucible  and  the  latter  gently 
heated  over  the  Bunsen  flame;  the  temperature  is  gradually  in- 
creased, care  being  taken  that  no  loss  occurs  through  boiling  over 
due  to  the  evolution  of  CO2.  When  the  mass  is  fused  the  crucible 
is  transferred  to  the  blowpipe  flame,  and  the  whole  is  kept  at  a 
bright  red  heat  until  bubbling  ceases  and  the  fused  mass  becomes 
tranquil.  The  flame  is  then  removed  and  the  crucible  is  allowed 
to  cool  just  below  redness,  when  it  is  placed  on  a  cold  surface,  such 
as  a  clean  block  of  iron,  in  order  to  assist  it  in  cooling  rapidly. 
When  cold  the  crucible  and  its  contents  are  placed  in  a  deep  evap- 
orating dish  or  in  a  shallow  beaker;  this  is  covered  with  a  large 
watch-glass  and  tolerably  strong  hydrochloric  acid  added  to  the 
contents,  which  should  be  gently  agitated  after  each  addition  of 
the  acid  and  kept  covered  during  the  operation.  When  efferves- 
cence has  ceased  and  the  crucible  is  free  from  all  adherent  solid, 
remove  the  crucible  by  means  of  the  crucible  tongs,  carefully  rins- 
ing off  any  adhering  liquid,  by  means  of  the  jet  from  the  wash- 
bottle,  into  the  main  portion  of  the  liquid.  On  treating  the  fused 
mass  with  HC1,  as  above  described,  most  of  the  SiO2  will  separate 
out  as  a  gelatinous  mass. 

If  any  gritty  particles  are  felt,  on  stirring  the  bottom  of  the 
vessel  with  a  glass  rod,  the  fusion  is  imperfect.  This  is  generally 
due  to  the  original  substance  not  having  been  powdered  sufficiently 
finely.  In  this  event  it  is  usually  more  satisfactory  to  make  a 
fresh  fusion,  taking  care  that  no  coarse  particles  are  present  in  the 
portion  of  the  sample  used  for  the  new  fusion. 

a.  Estimation  of  the  Silica. — The  liquid  containing  the  gelat- 


32  AMERICAN  GAS-ENGINEERING  PRACTICE. 

inous  silica  is  now  transferred  (if  necessary)  to  an  evaporating 
basin,  preferably  of  platinum  and  evaporated  to  dryness  upon  a 
water-bath.  When  the  contents  of  the  basin  become  pasty  they 
should  be  continually  stirred  with  a  rounded  glass  rod  to  prevent 
the  formation  of  lumps.  When  all  the  liquid  has  been  driven  off, 
the  contents  of  the  dish  should  then  be  in  the  state  of  fine  powder. 
In  order  to  expel  the  last  trace  of  HC1  the  dish  should  now  be  placed 
upon  a  sand-bath  and  heated  with  a  small  Bunsen  flame  until  no 
moisture  is  deposited  on  a  cold  clock-glass  when  placed  upon  the 
dish  for  a  few  seconds.  The  dish  is  then  allowed  to  cool  and  its 
contents  are  moistened  with  strong  HC1.  It  is  then  heated  on  a 
water-bath  for  about  half  an  hour,  a  small  quantity  of  hydrochloric 
acid  being  occasionally  added  with  stirring.  Hot  distilled  water  is 
now  added  and  the  silica  is  filtered  off  and  is  washed  free  from 
dissolved  chlorides.  The  precipitate  is  ignited  apart  from  the  filter, 
the  precipitate  being  transferred  to  the  platinum  crucible  cau- 
tiously, since  it  consists  of  a  very  light  powder  which  is  easily  blown 
away.  The  lid  is  placed  on  the  crucible  and  the  latter  heated, 
exceedingly  gently  at  first  and  the  temperature  raised  very  gradu- 
ally, or  the  escaping  steam  will  carry  some  of  the  fine  powder  away 
with  it.  The  crucible  is  finally  raised  to  a  full  red  heat  over  the 
Bunsen  flame  and  the  silica  weighed. 

b.  Estimation  of  Al?iO^  and  Fe203. — The  filtrate  from  the 
SiO2  determination  is  mixed  with .  NH4C1  solution  and  then  with 
NH4OH  in  slight  excess,  the  hydrates  of  iron  and  aluminium 
depositing  as  a  precipitate.  This  precipitate  is  washed,  and  dis- 
solved upon  the  filter  in  hot  diluted  hydrochloric  acid,  and  the 
solution  allowed  to  flow  into  a  nickel  or  porcelain  dish  contain- 
ing about  50  c.c.  of  pure  strong  KOH  solution.  Wash  out  the 
acid  which  remains  in  the  filter-paper  with  a  small  quantity  of 
distilled  water,  allow  these  washings  to  also  run  into  the  dish 
and  boil  the  contents  of  the  latter  for  a  few  minutes.  The  iron 
will  be  precipitated  as  ferric  hydrate,  while  the  hydrate  of  alu- 
minium will  remain  in  solution. 

The  iron  precipitate  is  filtered  out,  again  dissolved  in  HC1 
and  reprecipitated  by  NH4OH  in  order  to  free  the  ferric  hydrate 
from  KOH.  It  is  then  filtered,  washed,  ignited  apart  from  the 
filter  at  a  red  heat  and  weighed  as  Fe2O3.  The  filtrate  of  alu- 
minium hydrate  in  the  KOH  solution  is  treated  with  a  slight 
excess  of  strong  HC1,  and  then  with  a  very  slight  excess  of  NH4OH. 
The  precipitate  is  then  filtered  off,  washed,  dried,  ignited,  and 
weighed  as  A12O3. 

Another  method  of  separation  after  weighing  the  mixed 
hydrates  of  iron  and  aluminium  is  to  dissolve  them  in  KHSO4  and 
about  5  c.c.  of  H2SO4;  add  about  1  gram  hyposulphite  of  soda, 


THE  GENERATOR.  33 

boil  and  titrate  the  solution  with  a  1  per  cent  solution  of 
normal  bichromate  of  potash;  this  will  give  the  amount  of 
iron. 

c.  Estimation  of  Calcium. — If  the  volume  of  the  filtrate  from 
the  iron  and  alumina  precipitate  is  very  large,  evaporate  it  down 
to  a  convenient  bulk,  add  a  little  NEUOH  if  not  already  alka- 
line and  then  a  slight  excess  of  ammonium  oxalate.     Allow  the 
liquid  to  stand  and  the  precipitate  to  settle,  filter  off,  ignite  and 
weigh  the  precipitate  as  CaO. 

d.  Estimation  oj  the  Magnesium. — Evaporate  the  filtrate  and 
washings  from  the  calcium  oxalate  precipitate  to  dryness,  ignite 
the  residue  and  treat  it  with  a  little  strong  HC1;   add  water  and 
filter  if  necessary.    To  the  clear  solution  add  ammonium  hydrate 
in  moderate  excess,  and  then  an  excess  of  sodium  hydrogen  phos- 
phate solution.    Allow  the  liquid  to  stand  for  a  few  hours,  or 
shake  it  vigorously  in  a  stoppered  bottle,  filter  off,  wash  the  pre- 
cipitate with  dilute  ammonium  hydrate  solution,  then  ignite  it 
and  weigh  the  magnesium  as  Mg2P2O7. 

e.  Estimation  oj  the  Alkali  Metals. — Since    sodium  and  potas- 
sium carbonates  have  been  employed  in  the  fusion,  the  alkali 
metals  cannot  be  estimated  in-  the  filtrate  from  the  magnesium 
determination.     A   separate   portion   of   the   fire-clay   sample   is 
accordingly  used  for  their  determination.  Lawrence  Smith's  method 
for  the  determination  of  the  alkali  metals  will  be  found  the  most 
convenient.     The  following  is  the  mode  of  procedure : 

Weigh  out  accurately  about  1.5  grams  of  the  finely  powdered 
substance  into  a  platinum  crucible,  intimately  mix  this  with  a 
mixture  of  1.5  grams  of  pure  recrystallized  ammonium  chloride 
and  9  grams  of  pure  calcium  carbonate.  Then  either  heat  the 
crucible  to  bright  redness  for  an  hour  over  a  good  Bunsen  or  blow- 
pipe flame,  or  preferably  as  follows: 

Place  the  platinum  crucible  in  a  clay  crucible  containing  a 
little  calcined  magnesia  or  lime  at  the  bottom  and  round  the 
sides,  and  heat  the  clay  crucible  in  a  gas-furnace  which  is  capable 
of  maintaining  it  at  a  bright  red  heat.  When  the  crucible  has 
been  heated  for  an  hour,  allow  it  to  cool,  place  the  platinum  cru- 
cible and  its  contents  in  hot  water  hi  a  covered  platinum  or  por- 
celain dish  and  boil  for  a  time. 

This  procedure  will  dissolve  out  the  alkaline  chlorides  together 
with  some  calcium  hydrate.  Filter  and  mix  the  filtrate  with 
NH4OH  and  (NH4)2CO3  solutions  in  excess  and  with  a  few  drops 
of  ammonium  oxalate  solution.  Allow  the  liquid  to  stand,  filter 
into  a  platinum  or  porcelain  dish,  evaporate  the  filtrate  to  dry- 
ness  and  heat  the  residue  just  below  redness,  but  sufficiently 
strongly  to  drive  off  the  ammoniacal  compounds. 


34  AMERICAN  GAS-ENGINEERING  PRACTICE. 

Dissolve  the  residue  in  water  containing  a  few  drops  of 
NH4OH  and  ammonium  oxalate  solution  to  precipitate  any 
trace  of  calcium  compounds  still  in  solution;  filter,  evaporate 
the  filtrate,  heating  it  to  redness  in  a  weighed  dish  after  adding 
a  few  drops  of  HC1.  Gently  ignite  the  residue  and  weigh,  repeat- 
ing the  ignition  until  the  weight  is  constant.  The  weight  of  the 
residue  thus  obtained  gives  the  combined  weight  of  the  alkalies 
as  KC1  and  NaCl. 

The  residue  is  then  dissolved  in  water  and  the  potassium  chlo- 
ride is  precipitated  by  platinic  chloride  in  the  following  manner: 
To  the  solution  of  the  residues  a  few  drops  of  HC1  are  added, 
then  an  excess  of  platinic  chloride  solution,  the  liquid  being 
afterwards  evaporated  on  the  water-bath  until  a  semi-solid 
crystalline  mass  is  obtained.  The  platinic  chloride  is  seen 
to  be  in  excess  by  the  supernatant  liquid  being  of  an  orange 
color,  after  the  liquid  has  been  concentrated  to  a  small  bulk. 
When  it  is  certain  that  there  is  an  excess  of  platinic  chloride; 
we  may  then  proceed  according  to  either  of  the  following 
methods : 

1.  Pour  alcohol  upon  the  mass,  gently  shake  the  liquid  round 
in  the  dish  so  as  to  mix  the  contents  of  the  same  well  together, 
allow  the  precipitate  to  settle  completely  and  pour  off  the  liquid 
through  a  tarred  filter.     Repeat  these  operations  twice  and  finally 
transfer  the  undissolved  double  salt  to  the  filter  with  the  assistance 
of   a   small   wash-bottle   filled   with   alcohol.     Continue   washing 
the  precipitate  upon  the  filter  with  alcohol  until  the  washings 
are  no  longer  colored.      Dry  the  filter  and  its  contents  at  100° 
and  weigh  as  2KCl.PtCl4. 

2.  A  rather  quicker  method  of  treating  the  precipitated  double 
salt  is  to  wash  it  with  alcohol  by  decantation  until  the  alcohol 
is    no  longer  colored,   the    alcohol   being    decanted    through  an 
untarred  filter-paper.     Care  must  be  taken  that  as  little  as  pos- 
sible of  the  precipitate  is  poured  off  with  the  alcohol.    The  double 
salt,  freed  from  the  excess  of  PtCl,  is  now  washed  into  a  platinum 
crucible,  dried  at   100°  C.   and  weighed.    The  filter,  which  will 
contain  a  little  of  the  double  salt;  is  then  incinerated,  and  the 
ash  is  dropped  into   the   crucible  and  weighed.     By   deducting 
from  this  weight  the  weight  of  the  filter-ash,  the  approximate 
weight  of  platinum  left  by  ignition  is  found;    this  is  calculated 
into  double  salt  and  the  weight  is  added  to  that  of  the  double 
salt  already  found  in  the  crucible.     If  the  quantity  of  precipi- 
tate left  on  the  filter  is  appreciable,  the  weight  of  KC1  left  in  the 
filter-ash,  not   being   allowed  for,  will  introduce  an  error.    The 
filtei  in  this  case  should  be  ignited  in  a  separate  crucible,  the  KC1 
washed  out  from  the  ash  by  hot  water,  and  the  dried  residue 


THE  GENERATOR.  35 

weighed.    The  true  weight  of  the  platinum  in  the  ash  is  thus 
ascertained  and  is  made  use  of  as  mentioned  above. 

The  weight  of  the  sodium  chloride  in  the  mixed  chlorides  of 
potassium  and  sodium  is  then  ascertained  by  difference.  The 
chlorides  are  finally  calculated  as  K2O  and  Na2O. 


CHAPTER  II. 
THE  CARBURETTER. 

THE  carburetter  one  may  divide  into  two  topics: 

1.  That  pertaining  to  the  brick,  and  2.  That  to  the  oil,  oil- 
pump  and  appurtenances. 

Brickwork. — Of  the  first  it  is  difficult  to  lay  down  any  exact 
rule,  as  conditions,  the  class  of  oil,  and  the  class  of  brick  used 
greatly  alter  the  situation.  It  is  perhaps  well  to  have  a  brick 
neither  too  hard  nor  too  soft,  one  which  will  not  vitrify,  fuse, 
and  become  brittle  under  the  intense  heat,  nor  yet  crumble  from 
being  too  soft.  The  ideal  brick  is  one  in  such  a  condition  that 
it  attains  its  final  hardness  only  after  being  subjected  to  the  car- 
buretter heat.  Many  methods  are  in  vogue  as  to  the  laying  of 
brick  in  the  carburetter  and  the  use  of  "soaps."  These  ideas, 
however,  are  largely  a  matter  of  personal  preference,  as  is  the 
practice  of  "  coning  "  the  brick,  or  bringing  the  brick  up  to  the 
oil-spray  in  a  pyramidal  form. 

The  main  point,  however,  lies  in  close  attention  and  proper 
treatment  of  the  oil-spray,  which  should  be  examined  at  least 
every  coaling  period,  if  not  oftener,  and  freed  from  any  clogging 
material  or  other  hindrance  to  its  free  action.  This  item  of  oper- 
ation cannot  be  too  forcefully  emphasized,  as,  next  to  the  proper 
maintenance  of  an  even  heat,  it  presents  the  greatest  opportunity 
for  the  gas-maker  to  economize  material. 

The  bricks  of  the  carburetter  should  also  be  examined  periodi- 
cally and  replaced  as  soon  as  they  become  carbonized.  The  life 
of  bricks  depends  very  largely  upon  the  proper  handling  of  car- 
buretter heat,  for  improper  manipulation  of  this  heat  on  the 
part  of  the  gas-maker  very  quickly  clogs  and  carbonizes  them. 
This  is  especially  true  in  the  case  of  low  heat  and  the  crowding 
of  more  oil  on  the  machine  than  it  is  able  to  vaporize.  These 
heats  are  a  matter  of  much  discussion  and  diversity  of  opinion 
on  the  part  of  gas-makers,  the  author's  best  results  being  obtained 
by  a  condition  of  heat  which  shows  a  bright  orange  just  short 

36 


THE  CARBURETTER.  37 

of  a  white  tinge  at  the  completion  of  a  blast  and  a  cherry-red  at 
the  completion  of  the  run.  The  run  should  never  be  so  long 
nor  the  quantity  of  oil  turned  in  sufficient  to  "kill  "  the  heat 
of  the  carburetter  and  to  require  relighting  at  the  commencement 
of  the  blast. 

Regarding  the  cleaning  of  checker  brick  the  committee  of  the 
American  Gaslight  Association  states  as  follows: 

"The  checker  bricks  of  a  water-gas  apparatus  should  be  re- 
moved and  cleaned,  or  renewed,  when  dirty,  crushed,  or  disinte- 
grated. Checker  bricks  may  become  covered  with  a  non-conducting 
coating  of  ashes  or  carbon,  or  both,  making  impossible  the  desired 
exposure  of  the  oil-vapors  to  properly  heat  the  brick  surfaces. 
When  bricks  are  coated  or  saturated  with  carbon  the  surface  heats 
rapidly,  because  the  carbon  burns,  and  the  gas-maker  is  deceived 
by  the  glowing  carbon  and  believes  the  bricks  to  be  hotter  than 
they  are.  It  is  possible  to  tell  something  of  the  condition  of  the 
checker  bricks  by  observation  through  the  sight-cocks  provided  for 
the  purpose.  Other  indications  of  dirty  bricks  are  a  falling  off  in 
the  rate  of  make  per  minute  and  in  the  oil  results.  If  all  the  con- 
ditions of  operating  remain  unchanged,  and  the  candle  power  falls 
materially  and  stays  down,  and  the  make  of  gas  per  minute  of  run 
is  reduced,  the  checker  bricks  should  be  at  once  examined  and,  if 
dirty,  cleaned  or  renewed.  Bricks  should  not  be  allowed  to  become 
so  fouled  as  to  make  a  material  reduction  in  the  rate  of  make. 
Experience  soon  teaches  an  intelligent  gas-maker  to  avoid  both 
the  extreme  of  reduced  results  and  of  too  frequent  cleaning." 

Checker=brick  Spacing. — The  carburetter  and  superheater 
shells  are  not  only  lined  with  fire-brick,  but  are  filled  with  courses  of 
brick  with  spaces  between,  so  that  during  the  blast  these  bricks 
may  be  heated  to  the  degree  required  to  fix  the  oil-vapor  passing 
through  them  during  run  or  gas-making  period.  The  proper  spacing 
of  these  bricks  was  the  subject  of  an  article  published  in  Progressive 
Age  (Oct.  1,  1904,  p.  514)  by  J.  A.  Perry,  in  which  the  relation 
between  size  of  brick  and  space  between  bricks  to  obtain  the  best 
results  with  both  oil  and  fuel  was  developed  into  a  formula,  as 
follows,  for  size  of  brick  2.5x4.5X9  in.: 


9    \(2z+5)V 

where  F  —  flame  surface  of  checker  brick  in  vessel  after  deducting 

surfaces  in  contact,  in  square  inches; 

d  =  internal  diameter  of  fire-brick  linings  of  vessels,  in  inches; 
h  =  height  from  bottom  to  top  of  checker  brick,  in  inches; 
x = space  between  rows  in  each  course  of  checker  brick. 


OF    TH£ 

UNIVERSITY 

OF 
C>»/  HFOR1 


38 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


The  accompanying  curve  shows  the  relation  of  F  to  x. 
Suppose  Q  cubic  inches  of  gas  pass  through  the  total  space 

between  bricks  in  small  interval  of  time  t  and  #  =  - ,  M  is  a 

18 


i"     r     A-    2'     2V    3-     a-    4' 
FIG.  7. — Relation  of  Flame  Surface  to  Spacing. 


variable  coefficient  depending  on  the  temperature  and  specific  heat 
of  gases  and  brick,  and  H  is  the  B.t.u.  of  heat  absorbed  by  the 
checker  brick  during  the  blast  in  time  t,  then 


Q 


The  first  differential  coefficient  of  H  with  respect  to  x,  when  placed 
equal  to  zero  and  solved,  will  give  a  minimum  value  for  H.     Let 


Y= 


(2z+5)3 


then  the  value  of  the  first  differential  which  will  make  it  zero  is 
3.09  inches.     The  relation  of  Y  to  x  is  shown  in  Fig.  8. 

This  figure  shows  that  with  a  spacing  of  about  3.1  inches  the 
absorption  of  heat  by  the  checker  brick  is  a  maximum,  although 
there  is  not  much  difference  between  2.5-  to  4-in.  spacing  evident 
on  the  curve.  If  we  call  b  the  time  of  blast  in  minutes,  r  the  time 
of  run  in  minutes,  Vi  the  volume  for  gases  between  brick  in  one 


THE  CARBURETTER. 


39 


case  and  ¥2  this  volume  for  some  other  spacing,  G\  the  daily  make 
for  one  spacing  and  G2  the  volume  by  another  spacing,  then 


From  this  it  would  seem  that  3.1  inches  was  about  the  proper 
spacing  for  checker  brick  in  the  carburetter.    The  author  claims 


i"      r       ii*     2'      2i*     -3'      Vi'     f     4ii 
FIG.  8. — Relation  of  Brick  Spacing  to  Heat  Absorption. 

for  this  spacing  that  it  allows  a  quick  blow  with  high  blast,  saving 
of  fuel,  better  retention  of  heat  by  carburetter,  improved  oil  yields, 
and  increased  output  of  gas.  Close  spacing  keeps  the  temperature 
down,  and  wide  spacing  lets  it  rise.  Thus  for  a  2.5-in.  spacing  Y 
is  equal  to  0.2875  and  fora  1.25-in.  spacing  0.2371,  or  a  relatively 
lower  heat  absorption;  the  first  might  be  employed  in  the  car- 
buretter and  the  second  in  the  superheater  to  keep  the  temperature 
down  in  the  latter.  However,  with  small  spacing  a  hi^h  blast  is 
essential,  and  it  is  difficult  to  heat  the  carburetter  sufficiently  so 
that  its  brick  should  be  relatively  wide-spaced. 

Oil  Supply. — Another  item  concerning  which  opinion  widely 
differs  is  the  heat  at  which  the  oil  should  be  turned  into  the  car- 
buretter, many  gas-engineers  advocating  the  practice  of  vaporizing 
the  oil  prior  to  admission.  The  claims  made  for  this  method  are: 
1.  The  saving  of  fuel  due  to  utilizing  the  waste  heat  of  the  machine 
during  the  blast  in  heating  tue  oil;  2.  The  saving  to  the  checker 
brick  of  the  carburetter;  3.  The  more  perfect  decomposition  of  the 
oil 

The  efficacy  depends  somewhat  upon  the  individual  condition 


40 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


and  the  character  of  oil  used.  In  case  the  method  of  prior  vaporiza- 
tion should  be  adopted,  the  easiest  plan  is  to  connect  in  to  the 
pipe-line  a  return  bend-coil  (say  a  1.5-in.  pipe),  to  be  situated  in 


FIG.  9. — Oil  Preheater  in  Take-off  Pipe. 

the  take-off  pipe  of  the  superheater  (Fig.  9).  This  coil  may  be 
made  10  or  12  ft.  long  (depending  upon  the  size  of  the  machine) 
and  consist  of  some  6  or  8  coils,  it  being  possible  in  this  manner  to 


THE  CARBURETTER. 


41 


bring  up  the  oil  to  a  temperature  of  700°  or  800°  F.  prior  to  its 
admission  into  the  machine.  The  whole  principle  is  much  the 
same  as  that  of  the  feed-water  heater  and  economizer  in  steam- 
boiler  practice.  There  should  be  a  relief -valve  connected  in  series 
with  this  coil  and  emptying  back  into  the  measuring -tank.  Be- 
tween the  measuring-tank  and  the  coil  there  should  be  a  check- 
valve,  as  the  pressure  of  the  vaporized  oil  sometimes  rises  to  several 
hundred  pounds  per  square  inch. 


FIG.  10.— Oil-measuring  Tank. 

Oil=pump. — The  oil-pump  should  be  situated  below  the  measur- 
ing-tank and  before  the  oil-heater.  It  should  maintain  a  constant 
pressure  on  the  carburetter  of  from  60  to  70  Ibs.  per  sq.  in.  The 
piston-rods  of  this  pump  and  the  lining  of  the  cylinders  should  be 
of  brass  to  resist  the  action  of  the  acid  in  the  oil.  The  writer  has 
found  "Vulcabeston  "  packing  especially  applicable  to  oil-pumps. 
There  is  but  one  compound  which  has  ever  been  successfully  used 
in  making  tight  oil-pipe  joints,  and  it  consists  in  equal  parts  of 
white  lead,  red  lead,  coach  varnish,  and  dryers. 


42  AMERICAN  GAS-ENGINEERING  PRACTICE. 

It  will  be  noticed  that  the  author  has  referred  to  a  measuring- 
tank  instead  of  an  oil-meter,  although  either  may  be  used.  The  tank 
(Fig.  10)  is  a  simpler  device,  and  may  be  used  to  advantage  as  a  check 
even  where  the  meter  is  used.  The  oil  is  pumped  from  the  storage- 
tank  to  a  small  measuring -tank  fitted  with  a  glass  gage  having  a 
scale  calibrated  to  read  in  gallons  direct.  This  tank  is  pumped  full, 
and  the  connection  with  the  storage-tank  is  then  shut  off.  It  flows 
by  gravity  and  serves  as  a  head  upon  the  oil-pump,  which  then 
forces  it  into  the  carburetter.  It  is  at  all  times  accurate  and 
requires  none  of  the  frequent  adjustment  attendant  upon  oil-meters. 

Oil  Storage. — It  may  be  well  in  connection  with  the  carburet- 
ter to  note  the  oil-tanks  and  their  convenient  arrangement.  When 
a  tank-car  is  received  at  the  company's  siding  it  should  be  in- 
spected by  the  superintendent.  A  sample  should  be  taken  there- 
from and  a  hydrometer  test  made,  after  which  a  sample  should  be 
placed  in  a  flask  and  allowed  to  stratify.  As  oil  and  water  will 
form  a  mechanical  mixture  due  to  the  churning  of  the  car 
in  motion,  this  mixture  will  separate  and  stratify  if  left  undis- 
turbed for  a  sufficient  length  of  time.  Each  works  should  be 
supplied  with  a  copy  of  the  Tank  Gage  Handbook,  No.  2,*  giving 
the  capacity  of  every  tank-car  in  use  for  hauling  oil  in  the  United 
States.  It  is  well  to  have  one  tank  of  at  least  10,000  gallons 
capacity,  with  a  table  showing  its  capacity  at  various  depths  of 
oil.  This  tank  should  be  connected  in  series  with  any  other  stor- 
age-tank which  it  is  most  convenient  to  use,  in  solid  units  of 
5000,  10,000,  or  20,000  gallons  each.  An  exceedingly  flexible 
pipe  system  should  be  arranged  by  which  each  tank  can  be  con- 
nected to  the  main  line  or  any  other  tank.  In  this  manner  the 
storage-tank  can  be  used  in  units,  and  the  measuring-tank  for 
fractional  portions  in  the  checking  up  of  the  contents  of  arriving 
cars.  For  example,  we  will  assume  the  arrival  of  a  car  contain- 
ing 8000  gallons  of  oil.  One  tank  with  a  capacity  of  5000 
gallons  is  connected  to  the  tank-car  and  filled;  the  remain- 
ing 3000  gallons  is  then  turned  into  the  measuring-tank,  thereby 
enabling  the  superintendent  to  exactly  check  the  quantity  of 
oil  received. 

An  oil-car  is  considered  full  when  the  oil  level  is  flush  with 
the  top  of  the  tank,  where  it  is  joined  by  the  base  of  the  dome. 
Inasmuch  as  oil-producing  or  -shipping  companies  occasionally 
bring  up,  in  case  a  shortage  is  claimed,  the  question  of  tempera- 
ture, it  is  well  to  let  down  into  the  car  of  oil  a  thermometer  and 
to  record  its  temperature  for  future  reference. 

*  This  book  can  be  obtained  by  writing  to  the  Central  Traffic  Association, 
The  Rookery,  Chicago. 


THE  CARBURETTER.  43 

As  it  is  usual  to  have  oil-tanks  and  unloadings  occur  on  or 
near  sidings,  where  there  is  a  constant  passing  of  locomotives 
and  where  there  is  danger  that  sparks  may  fall  in  and  ignite  the 
oil  through  the  open  dome  of  the  tank-car,  a  hood  should  be  pro- 
vided to  screen  such  openings  and  at  the  same  time  permit  the 
passage  of  air  into  the  tank-car  in  order  to  prevent  the  tank  from 
becoming  air-bound. 

There  is  also,  especially  during  hot  weather,  a  vapor  which 
arises  from  these  oil-tanks,  and  it  is  well  to  put  a  connection  be- 
tween storage-tanks  and  the  holder  in  order  that  the  holder  pres- 
•sure  may  be  upon  these  vapors  and  at  the  same  time  permit  the 
gas  the  benefit  (if  any)  of  the  volatile  hydrocarbons. 

Great  care  should  be  taken  in  examination  of  the  spray  or 
oil-injector  of  the  carburetter.  This,  as  has  been  suggested, 
should  occur  at  frequent  periods  to  see  that  it  is  in  proper  work- 
ing order  and  that  the  oil  is  being  equally  distributed  over  the 
entire  surface  of  the  carburetter  brick.  Rotary  sprays  have  a 
tendency  to  clog  and  become  jammed,  thereby  concentrating 
the  oil  upon  a  limited  area  of  the  brick,  where  it  fails  to  evap- 
orate, is  carried  off  as  tar,  and  fouls  the  brick,  while  the  unsprayed 
portions  of  the  carburetter  become  unduly  hot  by  failure  of  the 
cooling  influence  of  the  oil;  this  burns  up  both  oil  and  brick, 
or  forms  naphthalene  in  such  of  the  hydrocarbon  vapors  as  even- 
tually escape. 

In  addition  to  the  test-lights  used  on  all  water-gas  sets,  it  is 
well  to  have  one  or  even  two  Knott  jet  photometers  connected 
in  series  so  as  to  check  each  other  on  the  inlet  of  the  storage- 
holder.  This  photometer  should  be  checked  by  comparison  with 
the  regular  bar-photometer  at  intervals  of  not  more  than  a  week. 

Grades  of  Oil. — Of  the  gas-oils  used  for  enriching  water-gas, 
the  three  most  common  forms  are  crude  oil,  known  as  BS  or  petro- 
leum, naphtha,  and  gas-oil.  Petroleum  is  the  oil  in  its  crude 
or  native  form  as  it  comes  from  the  well.  It  is  a  mixture  of  hydro- 
carbons, has  different  chemical  compositions,  varies  in  specific 
gravity  and  boiling-point,  and  can  be  broken  up  into  these  vari- 
ous substances  by  fractional  distillation.  The  chief  producing 
fields  for  crude  oil  are  the  United  States,  Russia,  and  Peru.  Penn- 
sylvania and  Ohio  crude  varies  in  specific  gravity  from  0.80  to 
0.85  (water  being  1).  Its  color  also  varies,  the  most  common 
being  a  dark  claret  color  by  direct,  and  a  greenish  color  by 
reflected,  light.  Oil  commences  to  distil  at  40°  C.  Some  of  the 
qualities  of  oil  which  make  it  suitable  for  gas-making  are  as  fol- 
lows: It  should  be  as  nearly  as  possible  free  from  water;  the 
residue,  after  distillation,  should  not  exceed  1  per  cent.;  only 
the  last  fraction  should  be  of  a  pronounced  dark  color;  the  rapid 


44  AMERICAN  GAS-ENGINEERING  PRACTICE. 

blackening  of  lead-acetate-impregnated  paper  should  not  take 
place  until  far  along  in  the  distillation;  under  ordinary  circum- 
stances the  first  distillate  should  be  nearly  colorless,  later  becom- 
ing an  amber  or  pale  straw  tint,  only  the  last  fraction  indicating 
a  decided  brown.  The  flashing-point  for  this  class  of  oil  is  usu- 
ally between  120°  and  250°  F. 

Naphtha  is  a  general  term  given  to  those  distillates  of  oil 
which  are  given  off  during  fractional  distillations  of  crude  oil, 
between  gasoline  and  lamp-oil;  this  oil  is  volatile  and  very  in- 
flammable, its  gravity  running  from  0.67  to  0.74. 

What  is  commercially  known  as  "gas-oil"  is  a  general  name 
given  to  those  distillates  between  the  lamp-oil  and  lubricating- 
oil  series;  this  oil  has  so  high  a  boiling-point  and  is  so  heavy 
as  to  be  useless  for  illuminating  purposes,  while  it  is  not 
sufficiently  viscous  to  be  used  as  a  lubricant.  As  a  matter  of 
fact,  however,  this  term  covers  a  multitude  of  odd  distillates, 
or  "  waste  oil  "  unfit  for  other  purposes,  and  as  a  result,  so-called 
gas-oil  varies  in  color,  gravity,  and  constituents,  its  average  gravity 
being,  perhaps,  about  0.85.  By  reason  of  these  variations  in 
gravity,  boiling-point,  etc.,  it  requires  most  careful  handling  on 
the  part  of  the  gas-maker,  and  he  must  constantly  vary  his  heat 
in  compliance  with  the  strata  of  oil  which  he  is  taking  from  the 
tank,  the  manipulation  of  which  requires  much  judgment  and 
long  experience. 

Chas.  F.  Cattell  mentions  the  economical  use  of  20  per  cent, 
of  water-gas  tar,  with  80  per  cent,  of  oil  as  a  water-gas  enricher, 
the  apparatus  in  use  being  a  six-foot  Lowe  machine,  ordinarily 
using  20  gallons  of  oil  and  a  make  of  from  4300  to  4800  cubic 
feet  of  gas  per  run.  Separate  tanks  and  sprays  were  used  for 
injecting  the  tar,  the  tar  being  admitted  to  the  generator. 

Oil  Analyses. — Concerning  the  method  of  examination  for 
gas-making  oils,  the  following  is  extracted  from  Butterfield's 
excellent  treatise  on  Gas  Manufacture: 

"The  laboratory  examination  of  an  oil  to  determine  its  fit- 
ness for  gas-making  embodies  the  operations  described  here- 
under.  The  specific  gravity  of  the  oil  and  its  temperature  at 
the  time  of  taking  the  specific  gravity  are  ascertained.  A  hydrom- 
eter with  an  open  scale  serves  for  taking  the  specific  gravity  if 
the  instrument  is  known  to  be  correctly  calibrated.  The  scale 
should  be  sufficiently  open  to  allow  reading  accurately  to  within 
0.0005;  the  thermometer  should  be  in  the  oil  while  the  reading 
is  being  made  and  be  read  immediately  after  the  hydrometer. 
Failing  the  use  of  an  accurate  hydrometer,  the  specific  gravity 
must  be  taken  in  the  ordinary  way  with  a  specific-gravity  bottle, 
but  the  high  coefficient  of  expansion  of  petroleum  renders  care-? 


THE  CARBURETTER.  45 

ful  and  rapid  working  necessary,  and  care  is  requisite  to  obtain 
correctly  the  temperature  of  the  oil  at  the  time  of  weighing.  By 
either  method  it  is  desirable  that  the  specific  gravity  should  be 
taken  at  the  standard  temperature,  usually  60°  F. ;  but  as  this 
is  generally  impossible,  it  should  be  corrected  to  that  tempera- 
ture by  means  of  the  coefficient  of  expansion  of  the  oil,  which 
may,  in  general,  be  taken  at  0.00036  per  degree  Fahrenheit  as 
an  average  value  for  petroleum  oils.  Oil  is  frequently  bought 
and  sold  by  v/eight,  which  is  calculated  from  its  volume  and 
specific  gravity,  hence  the  accurate  determination  of  the  latter 
has  special  importance  in  many  cases. 

"The  flashing-point  of  burning  oil  is  determined  in  England 
by  the  apparatus  devised  by  Sir  Frederick  Abel  and  adopted 
as  the  standard  by  the  Board  of  Trade.  For  oils  of  low  flash- 
ing-point it  is  equal  or  superior  to  any  of  the  forms  of  apparatus 
adopted  in  other  countries.  A  description  of  the  method  of 
making  a  determination  with  it  is  given  with  each  apparatus, 
and  there  will  be  little  divergence  in  the  results  obtained  by  differ- 
ent operators  if  the  directions  are  implicitly  followed.  Most  oils 
suitable  for  retorting  have,  however,  fairly  high  flashing-points, 
and  the  determination  can  be  made  with  sufficient  accuracy  hi  a 
much  simpler  apparatus.  This  consists  simply  of  a  cylindrical 
copper  vessel,  about  3  inches  in  diameter  and  3  inches  deep. 
The  lid  overlaps  the  top  of  the  cylinder,  but  a  flange  £  inch  deep 
attached  to  it  fits  within  the  cylinder  and  keeps  the  lid  in  posi- 
tion. The  lid  is  perforated  in  two  places:  one  hole  is  for  the 
insertion  of  the  thermometer  held  by  a  perforated  cork  fitting 
the  orifice ;  the  other  is  covered  by  a  small  lid  pivoted  to  the  cylinder 
cover,  so  that  the  opening  can  be  exposed  by  sliding  the  lid  from 
it,  and  can  be  covered  again  immediately  after  each  application 
of  the  test  flame.  The  oil  to  be  tested  fills  the  cylinder  to  a  height 
of  2  inches,  and  the  bulb  of  the  thermometer  is  immersed  in  the 
liquid  when  the  cover  is  in  position.  Heat  is  applied  to  the  bot- 
tom of  the  cylinder  by  means  of  an  Argand  burner  and  a  sand- 
bath,  so  that  the  temperature  of  the  oil  rises  about  1°  F.  per 
minute.  As  each  degree  of  the  thermometer  scale  is  reached 
the  opening  in  the  cover  is  exposed  and  a  small  gas  flame  passed 
over  it.  If  no  flash  is  observed,  the  opening  is  closed  until  the 
next  trial  is  made.  The  temperature  at  which  the  flash  is  first 
observed  is  noted,  and  recorded  as  the  flashing-point  of  the  oil. 
If  it  is  wished  to  confirm  the  result  a  fresh  portion  of  the  oil  must 
be  taken  for  a  second  determination,  as  oil  that  has  once  flashed 
will  not  again  flash  at  its  original  flashing-point.  The  gas  flame 
used  for  testing  should  be  J  to  £  inch  in  length,  and  is  readily 
obtained  by  fusing  the  end  of  a  piece  of  hard  glass  tube  until 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


the  orifice  allows  only  sufficient  gas  to  pass  through  at  its  or- 
dinary full  pressure  to  give  that  length  of  flame.     For  accurate 
determinations  heating  the  cylinder  in  an  air-, 
water-,  or  oil-bath  may  replace  direct  heating 
by  an  Argand   burner.     The  apparatus  should 
be  protected  from  air-currents  during   the  de- 
termination.    It    is    illustrated   in   Fig.   11.     A 
more  elaborate  apparatus  for  determining   the 
flashing-point    of    gas-oils    is    the    Pensky-Mar- 
tens,    which   is   extensively   used   on   the   Con- 
tinent.    The    oil    is   gently    agitated    by    small 
wings  on  a  rotating  vertical  spindle,  while  the 
vapor  in  the  space  above  the  oil  is  more  strongly 
agitated  by  a  larger  fan  on  the  same  spindle. 
The    oil-container    is    heated    through    an    air- 
bath,  and  its  top  is  provided  with  a  perforation 
FIG.  11.  — Abel's    for  a  thermometer,  and  a  neat  device  for  ad- 
Flash-test  Appa-  mitting  the  flash- jet    as  required.     The  test  is 
ratus-  conducted  very  similarly  to  one  with  the  Abel 

apparatus.  The  Pensky-Martens  apparatus  gives  very  concor- 
dant results  with  the  oils  of  high  flashing-point,  for  which  it  has 
been  devised.  The  flashing-point  is  usually  stated  in  the  Fahren- 
heit scale  in  this  country. 

"The  distillation  of  a  sample  of  oil  gives  much  valuable  infor- 
mation as  to  its  properties.  For  most  purposes  it  may  be  con- 
veniently carried  out  in  the  laboratory  in  the  manner  here  described. 
A  glass  spheroidal  flask  with  a  glass  tubulure  fused  in  its  neck,  of 
capacity  twice  the  volume  of  the  oil  to  be  distilled,  is  taken,  and  a 
thermometer  is  inserted  in  the  neck  by  means  of  a  tightly  fitting 
perforated  cork,  so  that  the  bulb  of  the  thermometer  is  on  a  level 
with  the  mouth  of  the  tubulure.  The  latter  is  connected  to  a 
Liebi's  condenser.  The  neck  of  the  flask  is  lightly  held  by  a  clip, 
and  the  bottom  rests  on  wire  gauze,  while  the  sides  of  the  flask  are 
jacketed  with  the  same  material  to  protect  them  from  air-currents. 
Heat  is  applied  by  means  of  an  Argand  or  rose  burner  at  first, 
though  towards  the  end  of  the  distillation  a  Bunsen  may  be  needed. 
A  convenient  quantity  of  oil  for  distillation  is  500  or  even  250  c.c. 
The  flask  should  be  weighed  before  and  after  the  oil  is  put  in  it, 
and  thus  the  weight  of  the  oil  taken  is  known.  The  heat  should 
be  regulated  so  that  the  distillate  drops  from  the  en:l  of  the  con- 
denser at  a  uniform  rate,  and  does  not  come  from  it  in  a  stream. 
The  temperature  is  read  on  the  thermometer  when  the  oil  begins 
first  to  pass  over,  and  afterwards  as  each  fraction  of  the  distillate 
is  removed.  The  distillate  is  usually  collected  in  fractions  amount- 
ing to  10  per  cent,  of  the  volume  of  oil  under  distillation.  The 


THE  CARBURETTER.  47 

specific  gravity  of  each  fraction  is  ascertained  approximately.  The 
distillation  is  pushed  until  increased  heat  drives  over  no  more  oil, 
and  no  residue,  or  coke  only,  remains  in  the  flask.  When  cool  the 
flask  is  again  weighed,  and  the  weight  of  the  residue  so  found 
enables  its  percentage  (by  weight)  of  the  oil  to  be  calculated.  The 
weight  of  each  fraction  of  the  distillate  can  be  found  by  direct 
weighing  or  from  the  specific  gravity.  The  total  of  the  weights  of 
the  distillates  and  the  weight  of  the  residue  should  amount  nearly 
to  the  weight  of  oil  taken;  the  deficiency,  which  should  not  exceed 
1  per  cent.,  may  be  recorded  as  'loss  on  distillation.'  It  is  due  to 
some  of  the  more  volatile  distillate  .escaping  condensation.  With 
many  oils  it  is  desirable  to  use  two  thermometers — one  for  tem- 
peratures from  20°  to  150°  or  200°  C.,  the  other  (nitrogen-filled) 
for  higher  temperatures.  A  thermometer  which  has  been  used  at 
high  temperatures  is  not  accurate  for  low  ones.  The  amount  of 
water,  if  any,  which  comes  over  and  settles  beneath  the  oily  dis- 
tillate should  be  observed.  The  color  of  each  fraction  should  be 
recorded,  and  a  piece  of  moist  lead  paper  held  above  the  outlet  of 
the  condenser  at  intervals  to  find  if  sulphureted  hydrogen  is 
evolved  at  any  stage  of  the  distillation.  The  degree  of  blackening 
gives  an  indication  of  the  amount  of  sulphur  in  the  oil.  A  note 
should  be  made  of  all  observations,  and  the  results  of  the  distilla- 
tion should  be  recorded.  The  determination  of  the  amount  of 
sulphur  in  gas-oil  is  seldom  made,  but  can  be  carried  out  by  Carius' 
method,  or  by  a  slight  modification  of  the  fusion  methods  for  sul- 
phur in  coal,  or  by  burning  the  oil  in  a  suitable  lamp  and  passing 
the  products  of  combustion  through  a  washer  of  hydrogen  peroxide 
or  other  suitable  oxidizing  agent,  and  estimating  the  sulphate  as 
the  barium  salt. 

"A  good  oil  for  gas-making  should  be  free  from  water  and 
leave  less  than  1  per  cent,  of  coke  on  distillation.  A  crude  oil  will 
generally  contain  fractions  distilling  below  100°  C.,  but  the  dis- 
tillate now  so  largely  employed  for  gas-making  will  be  free  from  such 
light  fractions.  A  natural  oil  general^  contains  water,  though 
sometimes  only  in  small  quantities,  and  there  is  great  divergence 
in  the  boiling-points  and  specific  gravities  of  the  fractions,  of  dis- 
tillate from  it.  Rapid  blackening  of  lead-acetate  paper  should  not 
take  place  until  near  the  end  of  the  distillation.  Only  the  tenth 
fraction  should  be  decidedly  dark  in  color.  Oils  containing  more 
residual  coke  than  1  per  cent,  may  be  used  in  certain  methods  of 
oil-gas  manufacture,  but  are  not  desirable  in  any  plant  containing 
checker-work  chambers  or  small  outlet  pipes.  Provided  the  dis- 
tillation results  do  not  condemn  an  oil,  it  is  tested  for  yield  and 
quality  of  gas  in  a  small  oil-gas  apparatus.  It  is  not  of  great 
importance  which  of  the  mimerous  forms  of  apparatus  in  common 


48  AMERICAN  GAS-ENGINEERING  PRACTICE. 

use  is  adopted,  but  the  same  should  be  used  during  a  series  of 
experiments,  and  comparisons  made  with  tests  of  a  standard  oil 
in  it.  Paterson's,  Keith's,  Pintsch's,  or  Avery's  apparatus  may  be 
used.  The  apparatus  should  be  of  a  size  to  work  off  a  gallon  of  oil 
in  about  three  hours.  The  heat  of  the  retort  or  tubes  must  be 
regulated  according  to  the  nature  of  the  oil  under  trial;  tests  should 
be  made  at  different  temperatures  to  find  that  most  favorable  to 
the  oil.  The  temperature  should  be  observed  with  a  Le  Chatelier 
or  other  good  pyrometer,  but  where  this  is  impossible  a  practiced 
eye  can  judge  it  with  fair  accuracy.  Not  less  than  a  gallon  of  oil 
should  be  gasified  at  each  test;  the  gas  should  pass  through  two 
lime  purifiers  (2  feet  square  by  1  foot  deep,  two  shelves)  and  then 
through  a  meter,  the  index  of  which  should  be  read  before  and 
after  the  test  to  find  the  quantity  of  gas  made.  The  temperature  of 
the  meter  should  be  observed  several  times  during  the  experiment, 
and  the  mean  temperature  and  mean  barometric  pressure  taken  for 
correcting  the  volume  of  gas  to  normal  conditions.  From  the 
meter  the  bulk  of  the  gas  passes  to  a  works  holder,  but  a  small 
stream  of  it  led  to  a  15-  or  20-ft.  holder  for  testing  purposes.  The 
pipes  should  be  thoroughly  cleared  of  air  before  this  sample  is 
collected,  and  the  stream  should  be  such  that  the  holder  is  filling 
throughout  the  test.  The  sample  is  tested  for  illuminating  power 
in  the  ordinary  way,  but  it  will  generally  be  necessary  to  try  several 
burners  to  find  that  most  favorable  to  the  oil.  The  highest  candle- 
power  found  with  any  burner  should  be  taken  for  calculating  the 
value  of  the  oil.  Care  must  be  taken  that  the  gas  in  the  small 
holder  is  thoroughly  mixed;  if  there  is  any  doubt  about  its  being 
so,  the  whole  of  it  should  be  burned  and  the  photometer  tests  taken 
as  the  illuminating  power.  As  a  general  rule  American  oils  give 
the  best  results  at  a  lower  heat  than  shale  oils,  and  the  latter  at  a 
lower  heat  than  Russian  oils.  The  results  of  the  tests  should  be 
worked  out  to  give  the  number  of  candles  produced  by  the  gas 
from  a  gallon  of  oil  burning  at  the  rate  of  1  cubic  foot  per  hour. 
As  the  standard  rate  of  5  cubic  feet  per  hour  is  too  fast  for  oil-gas, 
the  candle  power  at  the  actual  rate  of  consumption  is  taken ,  and 
the  nominal  candle  power  at  the  standard  rate  arrived  at  by  calcu- 
lation. The  product  of  the  number  of  candles  at  the  standard  rate, 
and  the  volume  of  gas  per  gallon  of  oil  divided  by  5  (the  number 
of  feet  burned  per  hour  at  the  standard  rate) ,  gives  a  figure  which 
represents  the  '  candles  per  gallon  ;  obtained  from  an  oil.  This 
figure  multiplied  by  3/175  gives  the  pounds  of  sperm  per  gallon  of 
oil.  The  pounds  of  sperm  per  gallon  divided  by  the  specific  gravity 
of  the  oil,  and  the  result  divided  by  ten,  gives  the  pounds  of  sperm 
per  pound  of  oil.  The  results  of  oil  tests  are  usually  stated  either 
in  ' candles  per  gallon  '  or  'pounds  of  sperm  per  pound  '  of  oil. 


THE  CARBURETTER.  49 

"In  the  United  States  of  America  crude  oils  are  extensively 
used  for  gas-making.  The  specific  gravity  is  about  0.830.  As  the 
oil  flashes  at  or  little  above  the  ordinary  temperature,  it  is  unsuited 
for  transport  to  a  distance.  It  gives  the  best  result  at  a  moderately 
low  heat.  In  consequence  of  the  much  larger  yield  of  burning  oil, 
American  oils  produce  less  intermediate  oil  on  distillation  than 
Russian  petroleum  affords. 

"With  the  exception  of  petroleum,  few  oils  are  worthy  of  con- 
sideration for  gas-making.  The  price  of  animal  and  vegetable  oils 
is  prohibitive;  the  only  others  available  are  the  dead  tar-oils.  As 
tar  is  a  product  of  destructive  distillation  at  a  high  temperature, 
it  is  evident  that  it  will  not  be  greatly  altered  in  character  by 
exposure  to  a  high  heat.  A  considerable  portion  will  merely  vola- 
tilize and  condense  again  unchanged  on  contact  with  a  cool  surface. 
The  light  benzene  hydrocarbons  will  act  thus,  likewise  naphthalene 
and  other  closed-chain  hydrocarbons.  The  green  oil  from  coal-tar, 
which  remains  after  the  extraction  of  phenols  and  naphthalene 
from  the  middle  oils  of  the  tar-distiller,  contains  a  certain  amount 
of  gasifiable  hydrocarbons  and  is  sometimes  used  for  gas-making. 
A  high  heat  is  required  to  produce  a  permanent  gas  'from  it,  and 
the  illuminating  power  is  always  low.  Coal-tar  '  green  '  oil  yields 
about  350  candles  per  gallon.  Oil-tar  as  deposited  in  the  con- 
densers and  siphons  of  an  oil-gas  installation  contains  about  a 
quarter  of  its  volume  of  intermediate  oil,  which,  when  sep- 
arated by  distillation  and  freed  from  naphthalene,  may  be  put 
through  the  apparatus  to  produce  gas.  The  yield  is,  however, 
only  about  300  candles  per  gallon,  and  the  gas  is  of  dubious 
permanency. 

"Hirzel  has  proposed  to  take  as  a  standard  gas-oil  with  which 
results  from  other  oils  may  be  readily  compared,  one  which  gives  a 
yield  of  60  cubic  meters  of  gas  per  100  kilograms  of  oil;  the  gas,  at  a 
consumption  of  35  liters  per  hour,  having  an  illuminating  power 
of  7.5  standard  German  candles.  Expressed  in  English  terms,  such 
an  oil  would  be  one  of  which  1  ton  would  yield  21,650  cubic  feet  of 
gas,  having  an  illuminating  power  of  31.86  candles.  This  gives 
137,980  candles  per  ton,  which  is  considerably  lower  than  the 
value  for  most  gas-oils  in  use  in  this  country.  A  standard  of  com- 
parison for  gas-making  oils,  such  as  Hirzel  has  proposed,  would 
frequently  be  of  service. " 

Temperature. — The  heats  of  the  carburetter  can  be  controlled 
principally  in  three  ways :  either  by  reducing  the  heat  of  the  entire 
set,  as  by  increasing  the  amount  of  steam  on  the  generator,  or 
adding  a  quarter  of  a  turn  of  down-steam  during  an  up-run,  or  by 
reducing  the  time  of  the  blasting  period  upon  the  generator.  More 
directly,  the  carburetter  heat  may  be  affected  by  reducing  either  the 


50  AMERICAN  GAS-ENGINEERING  PRACTICE. 

amount  of  blast  or  blasting  period,  or  by  "  blowing  cold/'  which  proc- 
ess consists  in  giving  the  carburetter  a  blast  considerably  in  excess 
of  that  given  the  two  other  retorts.  It  should  always  be  borne 
in  mind,  however,  that  the  heat  of  the  carburetter  should  be  re- 
tained considerably  in  excess  of  that  of  the  superheater;  the 
heat  may  again  be  changed  by  varying  the  amount  of  oil 
admitted. 

In  the  opinion  of  the  author,  it  is  extremely  inadvisable  to  heat 
gas-oil  before  its  admission  to  the  carburetter.  Gas-oil  being  a 
mixture  of  oils  of  various  gravities,  there  is  a  tendency  to  break 
them  up  at  too  high  a  temperature,  thereby  turning  the  lighter 
hydrocarbons  into  lampblack,  beside  permitting  the  carburetter  to 
"run  hot  ";  this  danger  is  less  likely  to  occur  with  naphtha  or 
crude  oil  having  a  regular  and  constant  gravity.  Theoretically 
there  is  some  saving  to  the  bricks  of  the  machine  by  the  prior 
heating  of  the  oil,  but  this  is  a  rule  more  than  offset  by  its  attend- 
ant difficulties. 

Value  of  Oils  for  Qas=making. — The  effort  to  utilize  coal-tar 
for  carburetting  in  water-gas  manufacture  has  not  been  successful, 
its  effect  having  been  unsatisfactory  upon  the  machines,  as  there 
is  a  tendency  toward  the  formation  of  lampblack.  It  is  main- 
tained that  the  best  oil  for  gas-making  is  that  which  contains  the 
largest  proportion  of  open-chain  hydrocarbons  (paraffins  and 
olefins)  and  the  smallest  quantity  of  the  ring  compounds  (aro- 
matic, etc.,  hydrocarbons).  The  latter  can  be  "  cracked  "  or  broken 
up  into  fixed  compounds  only  at  an  excessively  high  tempera- 
ture, and  their  illuminating  power  is  relatively  low.  Generally 
speaking,  gas-oil  should  be  composed  as  nearly  as  possible  of 
factors  that  are  homogeneous  (as  shown  by  the  fractions  and  dis- 
tillates coming  off  within  a  narrow  range  of  temperature).  It  will 
be  apparent  with  this  arrangement  that  at  a  given  heat  in  the 
fixing-chambers  the  oil  will  not  only  become  completely  dissociated, 
but  the  fractions  will  be  equally  gasified ;  whereas,  if  the  contrary 
were  true,  certain  fractions  would  become  gasified  to  the  destruc- 
tion or  loss  of  others,  the  extremes  being  indicated,  as  before 
mentioned,  by  the  production  of  lampblack  or  of  residual  oil  or 
tar. 

Messrs.  Leather  and  Ross  carried  on  an  extended  series  of 
experiments  (Journal  of  the  Society  of  Chemical  Industry,  May  31, 
1902),  as  a  result  of  which  they  suggest  that  an  approximate  valua- 
tion of  an  oil  for  gas-making  purposes  can  be  obtained  by  multiply- 
ing the  number  of  cubic  centimeters  of  gas  produced  from  1  c.c.  of 
oil  by  the  sum  of  the  hydrocarbon  vapors  plus  the  heavy  hydrocar- 
bons. They  give  tables  of  five  oils,  examined  by  gasifying  in 
retorts,  which  may  be  summarized  as  follows. 


THE  CARBURETTER. 


51 


RELATIVE  GAS-MAKING  VALUE  OF  VARIOUS  OILS. 


Line 
No. 

Russian 
Solar. 

Borneo 
Solar. 

American 
Solar. 

Texas 
Solar. 

Russian 
Refined. 

1 

2 
3 
4 

Cubic    centimeters    of 
gas  per  c.c.  of  oil.  ... 
ANALYSIS  OF  GAS. 
Hydrocarbon  vapors.  .  . 
Heavy  hydrocarbons  .  . 
Methane   

465.7 

4.0 
30.2 
54  2 

301.0 

4.0 
22.8 
60  0 

442.6 

3.2 
33.0 
52  5 

397.4 

3.4 
26.8 
66  2 

429.0 

3.8 
28.0 
57  0 

5 

Hydrogen  

12  0 

13  6 

11  6 

13  4 

11  5 

6 

Lines  2+3 

34  2 

26  8 

36  2 

30  2 

31  8 

7 

Lines  1X6 

15  927  0 

70670 

16  022  0 

12  001  0 

13  642  0 

Of  oils  of  different  types  they  found  that  in  general  those  con- 
taining the  greatest  proportion  of  paraffin  gave  the  best  results. 

Operation  Details. — It  is  possible  in  an  emergency,  where  it  is 
necessary  to  immediately  cool  the  carburetter  and  superheater  for 
the  removal  of  checker  brick,  to  either  remove  the  oil-injector  in  the 
case  of  the  carburetter,  or,  in  the  case  of  the  superheater,  to  intro- 
duce through  the  stack-valve  a  J-in.  pipe  to  which  a  hose  with 
water  supply  is  connected.  After  applying  the  water  a  short  time 
through  the  center  of  the  superheater  chamber,  it  may  be  intro- 
duced into  the  sides  through  the  manholes.  If  possible  the  water 
should  not  be  allowed  to  reach  the  side  and  thereby  loosen  the 
linings;  therefore  the  water  should  not  be  introduced  under  any 
degree  of  pressure.  The  carburetter  in  this  manner  should  be  cooled 
within  an  hour  and  a  half;  the  superheater  within  from  three  to 
four  hours.  It  does  not  pay  to  handle  hot  brick. 

In  checking  the  oil  received  in  gas-works  the  instruments  usu- 
ally used  are  the  Baume  coal-oil  hydrometer,  that  has  been  adopted 
by  the  United  States  Petroleum  Association,  and  Abel's  flash-test- 
ing apparatus.  In  testing  the  gravity,  corrections  for  temperature 
must,  of  course,  be  made;  it  is  also  necessary  in  some  instances  to 
ascertain  the  percentage  of  residue  in  the  oil.  The  most  rapid 
method  is  to  use  a  wide-mouthed  flask  which  has  been  previously 
weighed  and  the  outlet  of  which  is  connected  with  a  vacuum  pump, 
in  order  that  the  oil-vapors  may  be  rapidly  removed ;  after  distilla- 
tion and  cooling  the  flask  is  reweighed  and  the  residue  calculated. 

It  is  customary  with  a  number  of  water-gas  engineers  to  allow 
a  ratio  in  the  carburetter  of  250  No.  1  brick  (9X4^X2^)  for  each 
square  foot  of  surface  in  the  generator.  As  a  rule,  the  carburetter 
contains  one-third  and  the  superheater  two- thirds  of  the  brick ;  the 
total  number  of  fire-brick  used  for  fixing  water-gas;  however, 
depends  upon  a  number  of  variables. 


52  AMERICAN  GAS-ENGINEERING  PRACTICE. 

There  is  a  wide  difference  in  practice  regarding  the  pump  pres- 
sure to  be  maintained  upon  the  oil-nozzle  of  the  carburetter,  the 
extremes  employed  by  various  engineers  being  from  40  to  120  Ibs. 
It  is  likely,  however,  where  the  Collins  injector  is  used,  that  too 
great  a  pressure  will  spread  the  oil  into  so  wide  a  circle  as  to  strike 
the  wall  of  the  carburetter  and  will  run  down  without  vaporizing  ; 
on  the  other  hand,  too  low  a  pressure  causes  the  oil  to  drop  down 
to  the  center  of  the  machine,  with  practically  the  same  result, 
there  being  a  rapid  carbonization  on  account  of  the  limited  area  of 
fire-bricks  exposed:  the  engineer  determines  by  experiment  the 
results  best  applicable  to  his  conditions.  It  has  also  been  suggested 
that  with  high  heats  a  high  pressure  and  with  low  heats  a  low 
pressure  should  be  used,  the  vaporization  being  more  rapid  or 
slower  under  these  respective  conditions. 

The  oil-storage  capacity  necessary  in  a  water-gas  plant  depends 
upon  these  factors:  first,  candle  power  or  enrichment  of  the  gas 
made;  second,  the  quantity  of  gas  produced;  third,  the  distance 
of  the  plant  from  the  points  supplied  and  the  facility  of  communi- 
cation with  the  same.  Taking  into  consideration,  however,  strikes, 
accidents,  and  military  intervention,  the  minimum  should  not  be 
less  than  a  thirty  days'  supply,  from  which  we  obtain  the  formula 
for  necessary  storage  capacity: 


in  which  a  equals  gallons  of  carburetting  oil  required  per  1000  cu. 
ft.  of  gas  made  (usually  5);  V=  the  number  of  thousands  of  cubic 
feet  of  gas  made  in  24  hours,  t  the  least  number  of  'days'  supply 
necessary  (generally  30),  and  G  the  gallons  of  storage  capacity 
(generally  6V). 

The  gas  pressure  lost  on  passing  through  the  carburetter  and 
superheater  depends,  of  course,  upon  the  shape  and  number  of 
the  fire-brick  they  contain  and  also  on  the  pressure  upon  entering 
the  generator.  When  the  pressure  lost  in  passing  through  the 
generator  would  be  six  inches,  the  other  two  retorts  or  chambers 
would  have  a  drop  of  from  0.5  to  1  inch  each,  the  proportion  vary- 
ing with  the  spacing  and  condition  of  the  brick. 


CHAPTER  III. 
THE  SUPERHEATER.        ; 

WHERE  gas-oil  is  in  use  oily  vapors  of  a  dirty  yellow  color  and 
of  an  exceedingly  disagreeable  odor  are  apt  to  escape  from  a  machine 
upon  the  opening  of  the  superheater  stack-valve.  This  nuisance 
may  be  overcome  by  placing  a  pilot-light  adjacent  to  the  stack- 
valve,  which  will  ignite  these  vapors  immediately  upon  their 
escape  from  the  orifice  and  permit  of  their  consumption  before 
entering  the  outside  air. 

Temperature. — The  heats  of  the  superheater  should  be  main- 
tained at  a  lesser  temperature  than  that  of  the  carburetter,  for  the 
reason  that  in  the  last-named  retort  the  hydrocarbons  or  illumi- 
nants  are  "  cracked  "  or  broken  up,  and  that  further  "  cracking  " 
or  dissociation  tends  to  deteriorate  or  break  down  their  value.  It 
will  be  seen,  therefore,  that  the  purpose  of  the  superheater  is  for 
fixing  or  final  amalgamation,  and  for  this  purpose  must  be  materi- 
ally less  in  temperature  than  its  predecessor  the  carburetter.  The 
heat  generally  used  is  a  bright  cherry  in  the  upper  portion  of  the 
machine,  brightening  a  trifle  at  the  lower  sight-cock. 

The  tendency  of  most  water-gas  superheaters  is  to  "run  hot." 
It  is  possible  to  reduce  such  heat  by  "blowing  cold,"  or  giving  to 
the  superheater  a  blast  considerably  in  excess  of  the  other  retorts. 
This  is,  however,  rarely  advisable,  and  the  regulation  of  heat 
should  generally  be  through  the  medium  of  the  other  machines. 
The  heat  of  the  superheater  should  hardly  exceed  a  bright  cherry 
at  its  base,  with  a  duller  color  showing  in  its  upper  sight-cock,  a 
greater  heat  being  accompanied,  as  a  rule,  by  roaring  at  the  stack. 
As  has  been  before  stated,  the  heat  of  the  superheater  should  be 
invariably  less  than  that  of  the  carburetter,  the  office  of  the  super- 
heater being  to  fix  and  permanently  "set  "  the  gas,  and  not  to 
further  dissociate  the  hydrocarbons.  Perhaps  the  best  test  for  the 
proper  conditions  to  be  maintained  in  the  superheater  is  to  permit 
a  small  jet  of  gas  from  the  upper  sight-cock  during  the  run  to 
impinge,  through  a  very  small  nozzle,  upon  a  sheet  of  white  and 

53 


54  AMERICAN  GAS-ENGINEERING  PRACTICE. 

preferably  unglazed  paper.  Should  the  heat  of  the  superheater  be 
too  low,  tar  will  be  indicated,  while  a  cold  carburetter  or  excess  of 
oil  will  be  reflected  by  "uncracked  "  oil  being  carried  over  in  sus- 
pense. On  the  other  hand,  excessive  heat  on  the  part  of  the  super- 
heater will  be  shown  by  deposits  of  lampblack,  and  on  that  of  the 
carburetter  by  free  carbon.  The  proper  condition  of  heat  and 
"  well-cooked  oil  "  will  impinge  upon  white  paper  a  seal-brown 
stain,  varying  to  amber  and  slightly  glazed.  These  colors  will 
vary  slightly  with  particular  conditions  and  classes  of  oil,  but,  if 
carefully  watched  in  connection  with  the  results  made  by  the 
apparatus  and  the  conditions  noted,  form  a  most  exact  index  to 
successful  operation.  The  temperature  of  carburetted  water-gas 
upon  leaving  the  superheater  varies  from  1450°  to  1600°  F.,  this 
being  dependent  upon  the  heat  of  the  retorts  and  the  nature  of 
the  oil  used. 

Carbon  Deposits. — It  is  generally  possible  to  remove  the  carbon 
from  bricks  in  a  water-gas  superheater  by  "  burning  off."  This  is 
effected  as  follows:  The  set  having  been  let  down  and  all  dust  and 
ashes  removed,  the  doors  are  closed  and  a  slight  blast  turned  upon 
the  superheater,  which  is  then  ignited  by  means  of  a  little  oil  and 
a  red-hot  iron  rod.  This  slight  blast  is  then  maintained  until  all 
carbon  upon  the  bricks  is  entirely  removed,  the  process  usually 
taking  some  three  or  four  days. 

It  is  impossible,  as  a  rule,  to  work  this  process  upon  the  car- 
buretter, inasmuch  as  the  shock  attendant  upon  the  intermittent 
admission  of  oil  has  a  tendency  to  fuse  or  disintegrate  the  brick, 
thereby  "clogging  "  thegasway  of  the  machine. 

Carbon  is  not  formed,  as  is  sometimes  supposed,  in  the  take-off 
pipe  of  a  water-gas  superheater ;  it  merely  deposits  there,  and  such 
deposit  cannot  be  entirely  prevented.  It  can  only  be  reduced  in 
quantity,  its  presence  being  detected  by  continual  observation  of 
the  wash-box,  seat  drip-pot,  or  overflow.  Here  temperatures  are 
reflected  high  and  low  by  the  presence  respectively  of  lampblack 
and  unfixed  oil. 

The  color  of  crude  gas  leaving  the  superheater  is  affected  more 
or  less  by  the  nature  of  the  oil  being  used.  Under  average  condi- 
tions and  with  the  oils  usually  used  for  carburetting,  opening  of  the 
superheater  sight-cock  admits  crude  gas  of  a  golden  straw  tinge, 
without  indication  of  oil  or  lampblack.  Should  the  escaping  gas 
show  a  thin  bluish  tinge,  an  absence  in  the  proper  proportion  of 
hydrocarbons  is  indicated,  while  too  heavy  and  dense  a  cloud, 
snowing  tarry  or  oily  particles,  indicates  a  supersaturation  coming 
from  an  over-abundance  of  the  hydrocarbons  in  the  gas.  The  rich 
straw  color  and  a  certain  dryness  in  the  gas  are  under  average  con- 
ditions the  proper  mean  between  these  two  extremes.  When  a  jet 


THE  SUPERHEATER.  55 

of  this  gas  is  impinged  on  some  white  substance,  such  as  white 
unglazed  cardboard,  it  leaves  a  rich  golden  straw-colored  deposit, 
without  the  presence  of  either  tar  or  lampblack  being  in  evidence. 

The  number  of  brick  in  the  superheater  is  supposed  to  be  a 
certain  proportion  to  the  capacity  of  the  generator,  between  which 
retorts  there  should  exist  a  certain  balance;  as,  for  example,  when 
the  generator  is  ready  to  decompose  steam  the  superheater  should 
be  ready  to  fix  the  gas.  This  proportion  is  stated  by  one  authority 
as  follows:  The  combined  checker  brick  in  the  carburetter  and 
superheater,  exclusive  of  the  side  walls,  should  be  28  sq.  ft.  per 
gallon  of  oil  used  per  hour.  A  part  of  this  serviceable  area  is,  of 
course,  removed  from  direct  contact  with  the  gas,  by  reason  of 
the  contact  surfaces  between  brick  and  brick.  Therefore  the  figure 
is  better  given  as  20  sq.  ft.  of  brick  surface  per  gallon  of  oil  per 
hour.  These  figures  are  based  upon  the  use  of  the  heavier  oils, 
less  surface  being  requisite  in  the  case  of  the  naphthas  or  higher 
distillates. 

Superheater  Brick. — Split  bricks  (" soaps"),  of  course,  give 
greater  heating  surface  for  given  cubical  volumes  than  the  ordinary 
No.  1  brick,  but  their  use  is  rarely  necessary  inasmuch  as  the  fixing 
surface  in  modern  water-gas  machines  is  generally  excessive,  and 
the  soap  or  split  brick  are  weaker  and  less  durable  or  otherwise 
desirable  than  the  Standard  No.  1.  It  is  the  custom  of  many 
water-gas  engineers  to  place  in  the  superheater  twice  the  number 
of  No.  1  fire-brick  that  is  allowed  in  the  carburetter.  Each  set, 
however,  as  well  as  the  conditions  of  operation,  such  as  quality  of 
oil  or  generator  fuel  used,  length  of  blast,  hour  of  service,  etc., 
entails  different  conditions,  which  can  be  found  only  by  systematic 
and  careful  experiment. 


CHAPTER  IV. 
WASH=BOX  AND  TAR. 

THE  action  of  the  wash-box  or  seal  is  largely  similar  to  that  of 
a  check-valve,  to  prevent  the  return  of  the  gas  to  the  apparatus. 
These  seals  are  generally  made  with  a  ratio  between  the  wash-box 
and  the  dip-pipe  areas  of  about  25  to  1.  It  will,  therefore,  be 
obvious  that  if  the  dip-pipe  dips,  say,  3  in.  in  the  water  of  the  wash- 
box,  it  will  require  but  the  rise  of  3  in.  of  water  pressure  to  force 
the  gas  through  that  seal,  while  before  the  gas  can  return  from  the 
box  into  the  dip-pipe  all  the  water  in  the  box  would  have  to  be 
forced  back  into  the  dip-pipe.  Taking  the  area  ratio  at  25  to  1,  as 
before  mentioned,  while  it  takes  but  3  in.  pressure  to  force. the  gas 
into  the  box,  it  would  require  3X25  =  75  in.  pressure  to  force  the 
gas  back  into  the  dip-pipe.  (These  figures  are  only  approximate.) 
This  same  principle  can  be  observed  at  a  coal-gas  works  in  the 
action  of  the  hydraulic  main. 

Cleaning. — The  following  precautions  are  advised  by  the 
American  Gaslight  Association  committee  with  regard  to  the 
cleaning  of  a  water-gas  wash-box: 

"To  insure  safety  the  wash-box  and  connections  must  be  thor- 
oughly ventilated.  There  are  two  arrangements  of  wash-box  in 
water-gas  apparatus.  In  one  the  take-off  from  the  wash-box  is  on 
top,  and  in  the  other  it  is  on  the  side  and  connects  directly  with 
the  scrubber.  The  connection  from  the  gas  outlet  on  top  of  the 
superheater  to  the  wash-box  varies  in  different  forms  of  water-gas 
apparatus.  In  most  cases  there  is  a  lid  on  top  of  what  is  known 
as  the  oil-heater  connection,  which  can  be  opened  to  clean  the  oil- 
heater.  Where  no  oil-heater  is  used  the  take-off  connection  from 
the  superheater  has  a  hand-hole  cross  at  the  top  of  the  superheater, 
connecting  the  vertical  riser  from  the  wash-box  to  the  outlet 
branch  on  the  superheater.  Where  the  wash-box  has  a  take-off  on 
top  there  is  a  valve  between  the  wash-box  and  the  scrubber,  which 
can  be  closed  and  thus  shuts  off  communication  between  the  wash- 
box  and  scrubber.  In  this  case,  first  open  either  the  lid  on  top 

56 


WASH-BOX  AND  TAR  57 

of  the  oil-heater,  or,  in  case  there  is  no  oil-heater,  the  hand-hole 
on  the  cross;  then  shut  off  the  overflow  from  the  wash-box  to  the 
seal-pot,  open  the  hand-hole  on  top  of  the  wash-box,  and  fill  the 
wash-box  with  water.  When  the  wash-box  has  been  filled,  draw 
off  the  water,  open  the  hand-hole  or  manhole  on  side  of  wash-box, 
and  remove  the  tar,  etc.  In  case  there  is  no  valve  between  the 
wash-box  and  the  scrubber,  but  the  scrubber  and  wash-box  are 
joined  together  by  the  side  outlet  on  the  wash-box,  the  first  thing 
to  be  done  is  to  close  off  the  overflow-pipe  from  the  scrubber  to  the 
seal-pot.  Then  open  the  manhole  on  top  of  the  scrubber,  and 
then  the  lower  manhole  on  the  side  of  the  scrubber.  Fill  the  wash- 
box  with  water  as  described  above.  The  only  difference  in  the 
two  methods  is  that  in  one  case  you  must  thorou  hly  ventilate  the 
scrubber  in  the  manner  described.  In  any  case  take  care  that  no 
fire  comes  near  the  wash-box  or  connections  while  the  wash-box  or 
connections  are  open.  Do  not  use  a  light  abcve  the  work." 

Operation  Details. — The  wash-box  should  be  closely  watched 
as  a  check  upon  the  heats  in  the  carburetter  and  superheater.  If 
lampblack  is  being  produced  it  will  show  here,  as  will  sometimes 
naphthalene,  which,  however,  is  more  apt  to  appear  in  the  multi- 
tubular  condenser  and  the  inlet  of  the  purifiers;  on  the  other  hand, 
low  heats,  excess  or  unfixed  oil  will  appear  in  the  shape  of  free  oil 
on  the  surface  of  the  seal-pot.  The  safety  line  lies  about  the  exact 
center  of  these  extremes,  as  indicated  by  clear  tar,  showing  with 
reflected  light  a  tinge  of  yellow  gold,  its  exact  consistency  and 
color  being  dependent  somewhat  upon  the  nature  of  the  oil  used. 
To  repeat,  however,  the  best  test  of  properly  fixed  gas  is  the  clarity 
of  the  tar  at  this  point,  which  should  be  absolutely  free  from  either 
lampblack  or  uncracked  oil. 

The  inflow  of  the  wash-box  is  generally  regulated  so  as  to  admit 
from  7  to  11  gallons  of  water  per  1000  cu.  ft.  of  gas  made. 

The  question  of  increased  candle  power  through  illuminants 
picked  up  in  repumping  of  the  seal-water  is  much  debated.  There 
is  probably  some  recuperation  from  the  lighter  oil,  but  little  or 
none  from  the  tar,  which  is  better  extracted  by  a  skimmer  or 
baffle-separator  introduced  into  the  system.  There  are  certain 
little  advantages  in  the  use  of  fresh  water  in  the  seal,  as  it  more 
readily  combines  with  CO2  and  the  sulphur  compounds.  This  is 
more  than  compensated  by  the  high  temperature  usually  existing 
in  the  seal-water,  the  water  in  good  practice  in  any  event  never 
being  admitted  to  the  seal  at  a  less  temperature  than  110°  F.; 
moreover,  it  is  likely  that,  in  usmg  the  old  water,  it  has  already 
reached  a  point  of  saturation  for  both  gas  and  the  light  hydrocar- 
bons with  which  it  mechanically  combines,  it  therefore  ceases  to 
take  these  from  the  gas  passing  the  seal-pot.  The  best  practice 


58  AMERICAN  GAS-ENGINEERING  PRACTICE. 

requires,  therefore,  that  the  seal-water  be  returned  to  the  seal  by 
the  use  of  a  circulating  pump,  having  separated  from  it  all  tar, 
etc.,  which  is  heavier  than  water.  The  undecomposed  steam  in  the 
gas  should  also  be  utilized  here,  and  condensing  should  about  com- 
pensate for  any  losses  in  water,  thereby  obviating  the  necessity  for 
any  fresh  water  in  the  seal-pot  system.  The  pump  used  should  be 
of  special  design  for  handling  hot  water  and  oil,  and  should  have  a 
capacity  of  at  least  50  per  cent,  in  excess  of  its  maximum  demand. 
A  rapid  circulation  should  be  kept  up  in  this  water,  the  pump 
being  arranged  to  run  slowly. 

Where  tar  separators  are  used  the  suction-pipe  should  be  placed 
about  5  ft.  below  the  surface  in  the  last  section  of  the  separator, 
and  the  pump  may  then  force  directly  into  the  seal-pot. 

Composition  of  Tar. — O 'Conner,  in  his  Gas-engineers'  Hand- 
book, gives  the  amount  of  water  contained  in  oil-gas  tar  upon  leav- 
ing the  apparatus  as  being  70  per  cent. 

The  following  tar  analysis  is  taken  from  the  work  of  Paddon 
and  Goulden.  The  specific  gravity  of  the  tar  was  0.996. 

Per  Cent.  Per  Cent,  by  Volume 

by  Volume.  Without  Water. 

Water 76.5  0.00 

Benzine 0.28  1 . 19 

Toluol 0.90  3.83 

Light  paraffins,  etc 2.0  8.51 

Solvent  naphtha  (xylol)  ...                 4.15  17 . 96 

Phenol trace  trace 

Middle  oils  (naphtha,  etc.) .                6 . 92  29 . 44 

Creosote  oil  and  green  oil . .                5 . 70  24 . 26 

Naphthalene 0 . 30  1.20  per  cent,  by 

weight 

Anthracene  coke 0.22  (contains  8.33  0.93 

per  cent,  anthracene) 

Coke..                                               2.30  9.80 


99.27  97.20 

Loss.  .  0.73  2.80 


Total 100.00  100.00 

The  following  is  an  analysis  of  water-gas  tar  from  the  Mutual 
Gaslight  Company  of  Savannah,  Georgia: 

Specific  gravity  at  60°  F 1.1284 

Free  carbon 9.84% 


WASH-BOX  AND  TAR.  59 


DISTILLATION  PRODUCTS,  PER  CENT.  BY  WEIGHT. 

Ammoniacal  water 0.15 

Oils,  light— 170°  C 9. 18) 

Middle 25.81  [  62.76 

Anthracene 27 . 77  J 

Pitch 33.90 

Loss  in  analysis 3.19 


100.00 

Tar  Paint  and  Pavements. — The  two  principal  uses  of  oil-gas 
tar  are,  first,  as  a  paint;  and,  secondly,  as  a  paving.  Its  prepara- 
tion as  a  preservative  coating  for  pipes  and  metals  we  have  described 
under  the  head  of  Services. 

In  ordinary  paint  for  woodwork  it  may  be  boiled  down  to  such 
a  consistency  that  it  will  " string"  between  the  thumb  and  fore- 
finger. It  should  then  be  heated  to  about  150°  F.,  and  benzine 
added  at  the  proportion  of  1  gallon  of  benzine  to  4  gallons  of  tar. 
No  more  of  this  preparation  should  be  made  up  at  one  time  than  is 
required  for  half  a  day's  work. 

A  method  of  utilizing  oil-gas  tar,  which  has  been  employed  by 
several  companies  and  has  been  of  considerable  profit,  is  as  follows: 
An  oil-boiler  has  been  connected  with  the  tar- well,  a  tar-pump  being 
placed  in  series  therewith.  This  boiler  is  made  tight,  and  to  the 
top  is  fixed  a  pipe  coil  acting  as  a  worm  and  ending  in  a  suitable 
water-condenser. 

The  boiler  is  pumped  about  half  full  of  the  watery  tar  as  it 
reaches  the  well.  All  connections,  save  the  end  of  the  worm,  are 
then  closed  and  a  fire  started  beneath  the  boiler.  Evaporation 
takes  place  very  rapidly,  the  worm  first  passing  off  aqueous  vapor, 
then  anthracene,  and  finally  a  fair  quality  of  creosote.  The  residual 
left  in  the  boiler  or  body  of  the  retort  is  a  fair  quality  of  what  may 
be  termed  oil-pitch,  a  commodity  having  much  greater  value  as  a 
preservative,  painting,  or  roofing  material  than  has  the  ordinary 
oil-tar. 

The  following  formula  for  making  tar  pavements  or  side- 
walks is  given  by  a  committee  of  the  American  Gaslight  Associa- 
tion: 

"For  pavement  or  sidewalks  applied  as  a  finishing  surface  2  to 
3  in.  thick  upon  a  foundation  of  broken  stone  or  coarse  clinker, 
the  top  dressing  of  finer  ashes  or  coke  breeze,  boil  the  tar  until  at 
60°  F.  it  has  the  consistency  of  vaseline.  In  the  absence  of  special 
furnaces  for  the  work  place  a  sheet  of  boiler-plate  upon  stones  in 


60  AMERICAN  GAS-ENGINEERING  PRACTICE. 

the  vicinity  of  the  paving  to  be  laid,  so  that  it  will  be  about  one 
foot  above  the  ground.  On  this  plate  throw  building  sand  and 
underneath  kindle  a  fire  of  wood  or  coke.  Turn  the  sand  over  with 
a  shovel  until  well  heated.  Gradually  pour  on  the  thick  tar,  mean- 
while turning  and  mixing  the  mass  until  the  sand  is  uniformly  black 
and  of  such  a  consistency  that  a  ball  of  it  will  just  hold  together 
while  hot.  While  hot  and  carrying  the  mixture  in  heated  iron 
barrows  or  on  shovels,  apply  where  required,  leveling  with  a  hot 
rake  and  ram  with  a  hot  rammer.  Then  sprinkle  the  surface  with' 
fine  sand  and  roll,  using  preferably  a  heavy  hand  roller.  This  may 
be  made  of  a  piece  of  cast-iron  street  main,  with  ends  plugged  and 
center  filled  with  sand." 

Tar=pumps. — In  connection  with  the  handling  of  tar  and  con- 
cerning the  proper  pumps  for  the  transportation  of  same,  the 
committee  also  has  to  say  as  follows : 

"The  principal  points  of  valve  design  to  be  observed  are  that 
the  valves  should  afford  full,  free  openings,  and  that  the  seats 
should  be  so  arranged  that  no  lumps  of  heavy  tar  or  of  solid  matter 
in  the  tar  will  lodge  on  them  and  prevent  the  valves  from  closing 
tightly.  A  hinged  valve  is  better  than  the  ordinary  form  of  pump- 
valve,  since  in  the  latter  form  the  center  guide  obstructs  the  opening 
to  a  great  extent,  while  the  hinged  valve  affords  a  free  and  unob- 
structed opening.  These  valves  are  sometimes  used  with  horizontal 
seats  and  sometimes  with  seats  inclined  at  an  angle  of  45°.  With 
the  inclined  seat  there  is  less  danger  of  any  solid  matter  remaining 
on  the  seat  and  keeping  the  valve  open. 

"One  company  that  handles  a  great  deal  of  tar  employs  pumps 
in  which  the  valves  are  hinged  and  the  seats  horizontal,  and  says 
that  they  have  found  them  to  give  complete  satisfaction.  In  this 
case  the  valves  are  not  provided  with  springs,  being  prevented  from 
opening  too  far  by  stops  and  being  closed  by  their  own  weight  as 
soon  as  the  pressure  is  removed  from  beneath  them.  In  other 
pumps  springs  are  used  with  the  same  kind  of  valves  to  keep  them 
from  opening  too  far  and  to  assist  in  closing  them  promptly  when 
the  plunger  changes  the  direction  of  its  travel.  These  springs 
should  be  made  of  iron  or  steel." 

In  handling  tar  a  slow-running  pump,  preferably  of  the  rotary 
type,  should  be  used,  with  non-restricted  orifices,  all  parts  easy  of 
access  for  repairs  or  cleaning.  The  internal  resistance  of  the  pump, 
by  which  is  meant  the  resistance  offered  to  the  passage  of  the  tar, 
should  be  a  minimum.  If,  however,  the  reciprocating  type  of 
pump  should  be  used,  it  should  be  entirely  of  iron  or  steel  with 
ball-  or  trap-valves  and  with  extra  large  inlet  and  outlet.  The 
long  stroke-pump  will  be  found  preferable,  and  the  size  selected 
should  be  at  least  double  that  of  an  equal  capacity  for  water. 


UNIVERS1 


WASH-BOX  AND  TAR. 


61 


Separation. — There  are  two  occasions  when  tar  should  be  con- 
densed or  separated  from  its  accompanying  medium;  the  first, 
that  of  tarry  vapors  in  the  gas,  which  continue  as  far  as  the  puri- 
fiers and  greatly  injure  the  purifying  material  by  covering  it  with 
a  thin,  oily  insulation,  and  which  may  be  remedied  by  placing  in 
the  inlet  of  each  box  a  layer  of  planer  chips,  or,  better  still,  by 
devoting  the  first  box  in  the  series  entirely  to  chips  and  shavings, 
these  to  be  changed  immediately  upon  becoming  foul.  The  other 
occasion  is  the  separation  of  the  tar  from  the  water  with  which  it 
leaves  the  condensers,  scrubbers,  or  seal-pot.  This  separation  is 
extremely  advisable,  both  for  the  preservation  of  the  tar  and  the 
rendering  of  the  water  fit  for  renewed  use,  and  also  because,  in 
case  the  water,  either  as  a  whole  or  in  part,  is  not  used  again  or 
finally  finds  its  way  to  the  works  drains  or  sewers,  it  should  be 
free  from  all  tar  and  heavier  oils,  which  are  of  incalculable  detri- 
ment to  it.  It  is  the  custom  of  many  cities  to  prohibit  the 
running  of  tar  into  their  sewerage  systems,  and  inasmuch  as  it 
discolors  any  neighboring  watercourse  its  disposal  through  drain- 
age invariably  becomes  a  considerable  incubus. 

For  the  separation  of  the  tar  from  the  water,  however,  under 
conditions  such  as  we  have  just  recited,  a  form  of  separator  or 


FIG.  12. — Tar-separator. 

skimmer  is  illustrated  in  Fig.  12.  This  is  little  else  than  a  long, 
oblons;  trousfh,  in  which  the  greater  the  width  the  better,  the  veloc- 
ity of  flow  being  thereby  decreased.  In  this  trough  are  placed  lat- 
eral partitions  or  skimmers  marked  a.  The  intervals  between  them 
are  about  18  inches.  Alternate  partitions  reach  from  a  foot  above 
the  water-line  to  within  a  foot  of  the  bottom  of  the  box,  while 
intermediate  partitions  reach  from  about  4  inches  from  the  bottom 
of  the  box,  or  through  to  a  point,  say,  4  inches  beneath  the  water- 
line.  The  sides  of  the  trough  should  be  equipped  with  proper 
bungs  for  drawing  off  the  tar,  and  to  insure  perfect  separation  the 
outlet  of  the  trough  should  be  so  arranged  that  a  strainer  of  bag- 
gins;  or  fine  wire  netting  can  be  applied,  cotton  bagging  being  a 
very  good  material.  In  addition  to  the  above  separator  it  is  well 
to  have  upon  the  outlet  a  trough  which  may  be  filled  loosely  with 
pieces  of  coke,  which  will  be  found  an  excellent  strainer,  as  the 


62 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


rough  side  of  the  coke  adheres  to  the  passing  tar  which  attaches 
to  it  and  serves  to  give  the  water  its  final  purification.  The  coke 
should  be  maintained  in  a  cleanly  condition,  the  fouled  coke  being 
burned. 

A  limited  amount  of  water-gas  or  oil-tar  can  be  used  to  some 
advantage  on  the  generator  of  a  water-gas  set,  and  will  be  found 
to  have  an  enriching  quality  of  between  5  and  6  candles  per  gallon. 
Not  more  than  one-half  gallon  of  tar,  however,  should  be  admitted 
to  1000  cu.  ft.  of  gas  manufactured.  The  tar  should  be  pumped 
into  the  top  of  the  generator  preferably  with  an  oil-spray,  similar 
to  that  used  on  the  carburetter. 

The  West  Chester  (Pa.)  Gas  Co.  is  using  a  cream-separator, 
such  as  are  used  by  dairies,  for  the  separation  of  water-gas  tar 
from  its  entrained  water.  A  similar  separator  for  this  purpose  is 
made  by  Messrs.  Geo.  Shepherd  Page  Sons  in  England. 


jccnoir    Vr  ire*/*    IHJCCTO*    rat    eufnea. 

FIG.  13. — Steam-spray  Tar  Burner. 

Burning  Tar. — The  chief  disadvantage  in  using  tar  in  com- 
bination with  oil  as  an  enricher  appears  to  be  the  clogging  of  the 
checker  brick  in  the  carburetter  and  superheater,  so  the  more  gen- 
eral practice  appears  to  be  burning  the  tar  under  the  boilers,  which 
is  generally  accomplished  by  the  ordinary  steam-jet  spray  before 
described.  An  excellent  method  for  preparing  tar  for  this  usage 
is  by  the  use  of  two  tanks,  in  the  larger  of  which  a  large  steam-coil 
is  inserted,  by  which  the  water  is  evaporated,  thus  leaving  a  pure 
oil-tar  residual.  This  tar  is  then  drawn  off  into  the  second  tank, 
from  whence  it  is  fed  directly  to  the  burner.  The  levels  of  these 


WASH-BOX  AND  TAR.  63 

tanks  should  be  arranged,  if  possible,  so  that  this  last  operation 
may  be  performed  by  gravity.  It  is  stated  that  2.6  gallons  of  oil- 
tar  are  equal  to  a  bushel  of  coke  as  fuel  under  steam-boilers.  A 
form  of  burner  is  shown  in  the  illustration  (Fig.  13). 

Newbigging's  Handbook  gives  6  gallons  coal-tar  as  being  the 
equivalent  of  three  bushels  of  coal  when  properly  fired  under  a 
boiler. 


CHAPTER  V. 
SCRUBBERS. 

As  a  matter  of  fact  the  seal-pot  or  wash-box  is  the  first  in  the 
series  of  purifying  apparatus  in  a  water-gas  setting,  but  the  passage 
of  the  gas  is  relatively  so  rapid  at  this  point  as  to  make  its  action 
extremely  imperfect,  and  the  first  heavy  duty  in  cleansing  and 
purification  devolves  upon  the  scrubber,  which  succeeds  the  wash- 
box  in  series  and  precedes  the  condenser. 

Operation  Details. — Great  care  should  be  taken  with  the  regu- 
lation of  water  in  this  apparatus,  as  a  surplus  tends  to  wash  out 
and  carry  off  mechanically  the  heavier  hydrocarbons. 

This  water  should  usually  be  the  overflow  from  a  multitubular 
condenser,  unless  this  should  run  too  high  in  temperature.  A 
fresh-water  connection  should  always  be  available  for  such  occa- 
sions, when  a  sufficient  amount  of  cold  water  may  be  admitted  to 
lower  the  gas  to  the  degree  required,  namely,  about  170°  to  190°, 
at  the  outlet. 

The  material  used  to  fill  scrubbers  is  generally  that  presenting 
the  greatest  possible  surface  to  the  action  of  the  gas  and  water. 
King's  Treatise  recommends  the  use  of  small  stones,  pebbles,  coke, 
brickbats,  tiles,  or  timber.  Of  these  materials  coke  is  perhaps  the 
best  by  reason  of  its  lightness,  although  it  has  a  tendency  to  crumble 
should  the  height  of  the  column  be  sufficient  to  produce  a  crushing 
weight. 

Trays. — Sir  George  Livesey  is  responsible  for  the  method  of 
using  trays  of  thin  boards  J  in.  thick,  3  in.  high,  and  spaced 
3J  in.  apart,  having  an  area  proportioned  to  the  diameter  of 
the  scrubber.  The  most  common  practice  is  to  use  boards  f  inch 
to  J  in.  thick,  4  inches  to  10  in.  high,  and  made  up  with  about 
J-inch  spaces  between.  These  trays  are  placed  horizontally  within 
the  scrubber,  tier  by  tier,  in  a  manner  known  as  "thatched,"  or 
one  tier  placed  so  that  its  length  is  at  right  angles  to  that  of  its 
predecessor.  Props  or  supports  are  usually  placed  at  certain  inter- 
vals to  allow  the  gas  to  redistribute  and  to  facilitate  the  removal 

64 


SCRUBBERS. 


65 


of  a  portion  of  the  tray  without  removing  the  entire  contents.  The 
relative  merits  of  such  trays  as  described  and  those  of  coke  are 
about  as  follows: 

For  the  coke,  lightness,  cheapness  (the  coke  may  be  burned 
after  it  becomes  saturated),  and  the  convenience  of  the  installation. 

That  claimed  for  the  boards  or  trays,  freedom  from  stoppage, 
ability  to  be  cleansed  and  used  again,  greater  contact  service  for 


ware/twee!..  j>tpnoninG 

FIG.  14. — Water  Distributors  for  Tower  Scrubbers. 

both  gas  and  water,  slower  speed  of  travel  of  gas,  greater  efficiency 
for  space  occupied. 

Sir  George    Livesey  gives  the  following  comparison  of  mate- 
rial for  each  cubic  foot  of  space  occupied: 

Contact  surface  of  coke,  8J  sq.  ft.  per  cu.  ft. 

Contact  surface  of  boards,  31  sq.  ft.  per  cu.  ft. 

Coke  occupies  J  cubical  contents. 

Boards,  J",  spaced  1"  centers,  occupies  J  cubical  contents. 

Sprays. — The  greatest  difficulty  to  be  overcome  in  wet  scrub- 
bers is  to  obtain  an  even  distribution  of  the  water-spray  over  the 


66  AMERICAN  GAS-ENGINEERING  PRACTICE. 

material.  There  are  for  this  purpose  a  number  of  devices,  some 
of  which  are  movable,  as  the  tourniquet  pattern  (see  Fig.  14).  But 
perhaps  the  more  practicable  are  such  devices  as  the  Gurney 
jet  and  the  radial  spray,  as  illustrated.  These  last-named  should 
be  carefully  regulated  as  nearly  as  possible  to  throw  an  equal 
amount  of  water  evenly  distributed  over  the  entire  area  of  the 
scrubber. 

Water  Analysis. — In  water  analysis  for  all  practical  pur- 
poses, it  is  customary  to  divide  the  operation  into  two  parts: 

1.  Total  Incrusting  Solids:   Oxide  of  Iron,  Calcium  Carbonate, 
Calcium  Sulphate,   Magnesium  Carbonate,   and  Magnesium  Sul- 
phate. 

2.  Non-Crusting   Solids:    Magnesium   Chloride,   Alkaline   Car- 
bonates, Alkaline  Sulphates,  and  Alkaline  Chlorides. 

In  a  rough-and-ready  analysis  it  is  usually  enough  to  begin 
with,  say,  muddy  water,  settled;  decant,  weigh  sediment;  filter, 
weigh  suspended  matter.  Take  250  c.c.  filtered  water  and  titrate 
with  decinormal  HC1,  using  methyl  orange  as  indicator.  This 
gives  total  alkalinity  of  carbonates.  To  the  same  sample  add 
excess  NH3,  precipitating  A12O3,  Fe2O3,  and  most  of  the  SiO2;  fil- 
ter, ignite,  and  weigh  oxides. 

Precipitate  calcium  in  this  sample  with  ammonium  oxalate; 
filter,  ignite,  and  weigh  as  calcium  oxide. 

To  the  filtrate  add  sodium  phosphate  and  more  ammonia; 
filter,  ignite,  and  weigh;  calculate  as  magnesia. 

To  this  filtrate  add  HC1  and  BaCl2;  weigh  as  barium  sulphate 
and  from  it  calculate  the  sulphuric  acid. 

On  a  second  250  c.c.  sample,  determine  chlorine  by  titrating 
with  standardized  silver  nitrate,  using  potassium  chromate  as 
indicator. 

The  probable  combinations  may  be  worked  out  thus:  Calcu- 
late all  magnesium  as  carbonate  (if  excess  of  magnesium  remains, 
calculate  as  sulphate);  combine  excess  of  CO2  with  calcium  (if 
further  excess  of  CO2  remains,  combine  with  sodium);  calculate 
remaining  calcium  as  sulphate,  remaining  sulphuric  acid  with 
sodium,  and  chlorine  with  sodium.  This  is  applicable  to  boiler 
waters  and  gives  reasonable  accuracy. 


CHAPTER  VI. 
CONDENSERS. 

THERE  is,  perhaps,  no  item  in  the  manufacture  and  distribu- 
tion of  gas  more  important  than  its  proper  condensation.  This 
should  lie  between  two  limits.  The  first,  and  probably  more  im- 
portant to  avoid,  the  sudden  cooling  of  the  gas,  contracts  the 
vapor  and  causes  a  precipitation  of  the  benzol  vapors  and  heavier 
hydrocarbons;  the  second  requires  that  all  condensation  should, 
if  possible,  be  removed  from  the  gas  before  leaving  the  works,  as 
otherwise  stoppages  in  the  mains,  produced  either  from  the  low 
heat  in  the  machine,  causing  tar,  or  the  high  heat,  forming  naph- 
thalene and  lampblack,  will  invariably  ruin  the  meters,  causing 
the  diaphragm  to  become  hard  and  stiff,  closing  services,  reduc- 
ing pressure,  forming  traps,  and  especially  affecting  Welsbach  or 
incandescent  burners. 

Temperature. — In  order  to  obtain  proper  condensation  a  care- 
ful study  of  the  prevailing  conditions  must  be  made  in  each 
case  and  test  of  the  temperature  of  the  gas  made  at  various  junc- 
tures in  its  passage  through  the  works.  The  writer  suggests  the 
following  approximate  temperatures  which  should  follow  as  the 
result  of  gradual  condensation: 

Outlet  of  Deg.  F. 

Wash-box 220 

Scrubber 170-190 

First  condensers 120 

Relief-holder 70 

The  last  depends  somewhat  upon  the  temperature  of  the  atmos- 
phere. 

It  is  manifest  that  in  order  to  prevent  shock  or  sudden  chill 
to  the  gas  the  coolest  gas  and  the  coolest  water  should  be  brought 
into  contact;  for  example,  cold  water  only  should  be  turned 

67 


68  AMERICAN  GAS-ENGINEERING  PRACTICE. 

into  the  last  condenser,  the  overflow  from  which  goes  back  into 
the  scrubbers  and  in  turn  into  the  seal-pot,  thereby  causing  the 
current  of  water  to  flow  in  opposite  direction  to  the  current  of 
gas,  the  water  gradually  warming  and  the  gas  gradually  cooling 
so  that  the  water  at  the  seal  is  almost  of  an  identical  heat  with 
the  gas,  being  warmed  throughout  its  passage;  while  at  the  relief- 
holder  the  gas  is  of  a  temperature  identical  with  that  of  the  water, 
being  cooled  throughout  its  travel. 

Jas.  S.  Mcllhenny,  engineer  and  superintendent  of  the  Wash- 
ington (D.  C.)  Gaslight  Co.,  has  designed  a  system  of  condensing 


/  FIG.  15. — Method  of  Ascertaining  Temperature  of  Gases. 

apparatus  which  very  nicely  proportions  and  graduates  this  cool- 
ing process,  and  which,  through  an  easily  controlled  mechanism, 
accurately  and  mathematically  apportions  the  exact  amount  of 
cooling  surface  necessary  to  the  gradual  cooling  of  any  given 
amount  of  gas.  This  apparatus  is  capable  of  accommodating 
itself  to  a  very  large  or  small  quantity  of  gas  output. 

Surface. — As  to  the  amount  of  condensing  surface  necessary 
to  properly  cool  a  given  amount  of  gas,  authorities  differ  very 
widely.  Butterfield,  one  of  the  best  English  authorities,  gives 
150  to  200  sq.  ft.  condensing  surface  per  1000  cu.  ft.  of  gas  passed 
per  hour.  Newbigging  gives  10  sq.  ft.  per  cu.  ft.  per  minute. 
Perhaps  one  of  the  best  is  Raissner's  rule  of  3.65  sq.  ft.  of  cooling 
surface  per  1000  cu.  ft.  per  24  hours  as  a  minimum  and  4.56  sq. 
ft.  per  1000  cu.  ft.  as  the  best  practice.  The  above  calculations 
were  made  for  atmospheric  condensers. 

In  multitubular  water-condensers,  wnere  the  difference  in 
temperature  between  the  gas  and  the  cooling  medium  can  be 
regulated  by  the  amount  of  water  admitted,  the  amount  of  sur- 


CONDENSERS.  69 

face  depends  naturally  upon  the  reduction  in  temperature  re- 
quired. Suppose  it  were  necessary  to  lower  the  temperature  of 
the  gas  63°  (that  being  the  extreme  difference  in  temperature 
between  the  gas  and  the  water  at  the  gas-inlet  of  the  condenser) 
to  an  average  difference  of  36.5°  F.,  it  would  then  be  necessary 
to  have  1.71  sq.  ft.  of  water-cooled  surface  and  1.19  sq.  ft.  of 
air-cooled  surface  per  1000  cu.  ft.  of  gas  per  day. 

If  the  water  is  passed  through  the  tubes  and  the  gas  outside 
the  tubes  in  the  condenser,  then  the  shell  usually  affords  about 
1  sq.  ft.  of  air-cooled  surface  in  addition  to  the  water  surface. 
When  the  gas  is  passed  through  the  tubes  there  is  no  air-cooled 
surface  except  the  small  amount  around  the  gas  spaces  at  the 
top  and  bottom.  These  condensers  will  show  average  differences 
in  temperature  between  the  gas  and  the  water  of  over  10°  F., 
and  their  great  difficulty,  as  is  almost  invariably  true  with  all 
water-cooled  systems  of  condensation,  is  that  the  chilling  of  the 
gas  is  too  sudden  and  a  precipitation  of  the  illuminants  thereby 
results. 

The  writer  is  of  the  opinion  that  the  burden  of  testimony  is  to 
show  that  at  least  8  or  even  10  sq.  ft.  of  water-cooled  surface 
should  be  installed  for  each  1000  cu.  ft.  of  rated  maximum  capacity 
per  day  of  the  condenser,  and  that,  such  apparatus  being  at  the 
command  of  the  works  engineer,  he  should  then  closely  watch 
the  temperature  of  his  gas  throughout  its  course,  and,  by  the  proper 
admission  of  water  into  the  water-inlet  of  his  last  condenser,  main- 
tain a  gradual  and  equal  cooling  throughout  the  entire  process. 

A.  G.  Glasgow  in  1892  made  the  statement  that  it  required 
90  gallons  of  water  per  1000  feet  of  water-gas  manufactured  for 
condensing,  cooling,  and  scrubbing.  Of  course  the  amount  of 
water  required  for  condensing  gas  to  any  given  temperature  will 
depend  largely  upon  the  area  of  the  condenser  and  atmospheric 
conditions. 

Essential  Principles. — Next  in  order  to  the  recuperation  of 
heat  lost  from  water-gas  sets  as  an  economic  condition,  the  subject 
of  condensation  is  most  important;  it  is  but  little  understood,  and, 
moreover,  is  so  dependent  upon  local  conditions,  environment,  cli- 
mate, etc.,  as  to  make  impossible  any  arbitrary  procedure  in  the  mat- 
ter. It  is  conclusively  proved  that  deposits  of  naphthalene,  freezing 
of  services,  and  the  various  troublesome  stoppages  are  positively 
prevented  by  the  thorough  drying  of  the  gas,  and  it  is  doubtful  if 
any  engineer  properly  realizes  the  improvement  in  service  rendered, 
especially  along  the  line  of  incandescent  lighting,  the  maintenance 
of  meters,  etc.,  that  would  ensue  upon  the  establishment  of  a  per- 
fect system  of  condensation.  Broadly  speaking,  in  the  opinion  of 
the  writer,  this  would  be  along  the  following  lines: 


70  AMERICAN  GAS-ENGINEERING  PRACTICE. 

The  passage  of  the  gas  should  be  slower  at  the  commencement 
of  its  condensing  course,  and  its  impinging  during  the  mechanical 
portion  of  its  passage  should  be  less  violent  than  later  on,  where 
the  gas  has  attained  a  somewhat  lower  temperature.  To  effect  this 
the  velocity  of  the  gas  should  be  slowest  at  the  beginning  of  its 
passage,  gradually  increasing  in  speed  throughout  its  course.  As 
it  gradually  decreases  in  temperature  there  is  a  shrinkage  in  vol- 
ume and  a  corresponding  precipitation  of  both  aqueous  vapors  and 
hydrocarbons.  The  loss  of  the  latter  is  considerably  less  where  the 
temperature  is  reduced  very  gradually  and  the  direction  of  the 
flow  of  gas  and  water  arranged  in  reverse  directions. 

It  must  be  remembered  that  the  affinity  of  gas  for  water  at  any 
temperature  is  very  great,  and  that  it  will  take  up  and  recombine 
with  substances  at  any  stage  of  manufacture  or  distribution,  the 
principal  points  of  contact  being  the  hydraulic  main,  seal-pot, 
scrubbers,  purifying-boxes,  station  meter,  and  the  water-seals  of 
the  holder,  the  last  named  being  much  more  important  than  is 
commonly  realized. 

The  writer  therefore  suggests  greater  condenser  capacity  with 
a  slower  rate  of  flow,  and  a  condenser,  dry  scrubber,  or  shavings 
purifier  containing  some  absorbent  to  be  placed  at  the  outlet  of 
the  storage-holder  or  immediately  adjacent  to  the  distribution 
outlet.  This  would  allow  but  one  remaining  chance  for  the  reab- 
sorption  of  condensed  materials,  such  as  are  found  in  the  drips  along 
the  mains.  These  drip-pots  should  be  maintained  as  clear  and 
free  from  deposits  as  possible,  a  matter  which  would  not  prove 
difficult  where  the  gas  handled  is  dry  and  originally  free  from 
moisture. 

As  has  been  before  said,  the  theory  of  condensation  requires 
that,  with  each  degree  of  decrease  in  temperature  on  the  part  of 
the  gas,  a  portion  of  aqueous  vapor  or  water  be  deposited;  and 
that  this  shall  be  done  gradually  and  without  excessive  friction 
upon  the  gas,  so  that  the  hydrocarbons  will  not  be  disturbed,  is 
the  fine  art  of  proper  condensation.  As  will  be  seen,  this  deposit- 
ing of  water  on  the  descending  scale  of  the  thermometer  is  theoret- 
ically directly  the  reverse  of  fractional  distillation.  Unfortunately 
this  does  not  work  out  completely  in  practice,  for  two  reasons, 
viz. :  first,  that  in  this  precipitation  the  entrained  hydrocarbons  are 
mechanically  separated;  and,  second,  the  aforesaid  affinity  of  gas 
for  water  under  any  condition  tends  to  its  recombination  at  any 
period  of  its  travels;  also  the  volume  of  the  gas  may  be  due  to 
pressure  as  well  as  temperature.  The  point  of  complete  saturation 
of  gas  for  hydrocarbon  vapors  is  extremely  uncertain,  the  behavior 
of  the  gas  being  different  under  varying  conditions,  environment, 
and  pressure.  It  would  seem  that  a  system  of  dry  condensation 


CONDENSERS.  71 

would  be  extremely  advantageous,  which  would  afford  the  gas  no 
opportunity  to  recombine  with  moisture,  for  this  recombination 
and  subsequent  precipitation  constitutes  a  washing  process  which 
eventually  removes  from  the  gas  a  considerable  proportion  of  its 
hydrocarbons. 

The  difficulty  has  been  that  any  dry  desiccating  material,  during 
its  first  stage  of  use  or  when  first  renewed,  would  act  too  harshly  upon 
the  gas,  mechanically  stripping  it  of  many  of  its  valuable  contents; 
while  later  on,  when  permeated  with  these  ingredients,  it  would 
reach  the  point  of  saturation  and  cease  to  act  at  all.  A  material, 
if  found,  which  would  maintain  for  any  length  of  time  the  mean 
between  these  points,  would  prove  a  valuable  aid  to  purification. 

There  is  no  doubt,  however,  that  the  gas  when  leaving  the  works 
should  be  perfectly  fixed  and  dry,  and  to  this  end  the  writer  again 
urges  the  efficiency  of  a  proper  condenser  at  the  outlet  of  the  storage- 
holder.  The  improvement  in  service  gained  through  the  supply 
to  the  consumer  of  a  perfectly  dry  gas  is  most  marked  not  only 
by  the  avoidance  of  naphthalene  and  various  deposits,  and  the 
damage  done  to  the  diaphragms  of  meters,  incandescent  mantles, 
ranges,  etc.,  but  the  removal  of  moisture  promotes  a  very  consider- 
able increase  of  candle  power,  in  addition  to  which  the  flat-flame 
light  is  whitened  and  materially  improved  in  color  and  luminosity. 

This  feature  has  been  proved  by  experiments  in  high-pressure 
transmission,  results  showing  that  about  65  per  cent,  of  moisture 
can  be  taken  out  of  the  gas  by  10  Ibs.  per  sq.  in.  compression, 
while  at  20  Ibs.  pressure  practically  all  moisture  disappears.  Pro- 
portionately, however,  the  greatest  amount  of  moisture  is  removed 
up  to  and  by  a  compression  to  6  Ibs.  per  sq.  in. 


CHAPTER  VII. 
PURIFIERS. 

Testing  for  Impurities. — The  following  are  the  simplest  quali- 
tative tests  for  ascertaining  the  presence  of  impurities  in  gas: 

For  carbonic  acid  allow  the  gas  to  bubble  through  lime-water; 
if  present  the  water  will  become  thick  and  cloudy. 

For  H2S  impinge  the  gas  through  a  pet-cock  on  a  piece  of  paper 
which  has  been  wet  with  acetate  of  lead  (sugar  of  lead)  in  solu- 
tion; its  presence  (H2S)  will  be  indicated  by  the  discoloration  of 
the  paper,  a  shade  of  brown  appearing,  the  amount  of  the  discolora- 
tion depending  upon  the  quantity  of  sulphureted  hydrogen  con- 
tained in  the  gas  and  the  length  of  time  given  to  the  exposure. 

A  similar  test  to  that  for  H2S  is  made  for  the  presence  of  am- 
monia, only  turmeric  paper  is  used  instead  of  acetate  of  lead. 

The  test  for  tar  is  usually  made  by  permitting  a  stream  of  gas 
to  impinge  upon  a  piece  of  white  (and,  better,  unglazed)  paper. 
If  the  paper  receives  a  dark,  dirty,  or  tarry  stain,  the  presence  of 
tar  in  the  gas  is  indicated.  A  continuous  test  for  tar  may  be  made 
by  passing  a  stream  of  gas  through  a  test-tube  loosely  filled  with 
cotton-wool,  in  which  case  should  tar  be  present  the  wool  will 
become  discolored. 

The  places  at  which  these  tests  should  occur  are  usually  such 
situations  as  would  indicate  the  complete  or  imperfect  gas  purifica- 
tion, as,  for  example,  the  test  for  ammonia  would  be  the  outlet  of 
the  last  scrubber  or  washer;  that  for  CO2  and  H2S  generally  at  the 
last  purifying -box  in  the  series;  and  that  for  tar  at  the  outlet  of 
the  tar-extractor,  condenser,  or  even  the  sight-cock  in  the  super- 
he^ater.  It  is  sometimes  necessary,  however,  to  make  tests  for 
tar  and  other  condensations  (for  which  purpose  the  cotton-wool 
test  is  preferable)  in  the  center  of  the  distribution  system,  or  at 
the  fixtures  of  some  consumer;  this  is  necessary  when  tar,  naphtha- 
lene, or  other  mechanical  impurity  is  causing  trouble  to  gas  arcs 
or  other  incandescent-lighting  burners. 

Purify  ing -houses  are  not  an  absolute  necessity,  as  it  is  possible 

•  72 


PURIFIERS.  73 

to  maintain  the  boxes  at  a  proper  temperature  by  means  of  a 
steam-coil,  although  it  is  the  experience  of  the  writer  that  even  in 
the  colder  climates  the  chemical  action  occurring  in  the  box  gen- 
erates sufficient  heat  to  deliver  .the  gas  at  the  outlet  at  an  equal 
temperature,  if  not  greater,  than  that  at  which  it  enters  the  box. 
For  exposed  work,  however,  he  strongly  recommends  boxes  of  the 
Doherty-Butterworth  type.  The  maintenance  of  such  boxes  is 
practically  reduced  to  the  annual  painting,  and  the  danger  of  explo- 
sion, due  to  the  formation  of  explosive  mixtures  in  purifying- 
houses,  is  entirely  obviated. 

Leaks. — In  leaks  in  holders  and  purifying-boxes  occurring  be- 
tween the  lap  of  the  plates  where  such  plates  are  too  thin  to  calk 
and  inclined  to  buckle  and  separate,  a  temporary  stoppage  can  be 
made  by  rolling  tin-foil  into  small  rolls  and  calking  in  between 
the  plates  with  a  sharp  tool,  after  which  the  whole  should  be  heavily 
shellacked. 

Precautions. — Explosions  have  often  occurred  in  purifying- 
houses  through  the  breaking  of  incandescent-light  bulbs.  This 
should  be  guarded  against.  Lamps  have  been  successfully  used 
with  a  double  screen,  increasing  the  size  of  the  wire  one-half. 

Preservation. — A  film  of  heavy  petroleum  or  lubricating-oil 
carried  upon  the  seals  of  purifying-boxes  tends  to  prevent  the 
rusting  of  their  sheets. 

Sulphur  Removal. — The  chief  reason  for  eliminating  sulphur 
and  sulphurous  compounds  from  gas  is  the  fact  that  they  burn 
to  sulphurous  oxide,  a  compound  disagreeable  to  breathe  and 
on  some  occasions  forming  exceedingly  small  quantities  of  H2SO4. 
The  amount  of  sulphur  in  gas,  however,  as  ordinarily  purified, 
is  too  small  to  be  appreciable. 

The  two  methods  of  purification  most  commonly  in  use  may 
be  stated  as 

1.  Purification  where   the  material  is  handled  for  revivifying, 
and 

2.  Revivifying  in  situ. 

It  is  not  the  desire  of  the  writer  to  discuss  the  various  advan- 
tages of  these  two  methods ;  they  depend  for  their  adoption  largely 
upon  the  relative  cost  of  labor  and  installation. 

In  the  in  situ  method  probably  the  best  plan  is  to  connect  a 
small  air-pump,  such  as  that  made  by  the  Connelly  Iron  Sponge 
&  Governor  Company,  in  such  manner  that  somewhere  in  the 
neighborhood  of  1  per  cent,  of  air  is  admitted  into  the  purifiers 
with  the  gas  and  thus  revivifies  the  oxide  from  the  effects  of 
the  sulphureted  hydrogen.  Even  with  this  method,  however, 
the  oxide  must  be  periodically  changed,  as  it  becomes  foul  with 
tar  and  oil;  also  the, moisture  in  the  gas  eventually  causes  the 


74  AMERICAN  GAS-ENGINEERING  PRACTICE. 

oxide  to  crystallize  and  become  hardened,  thereby  materially 
increasing  the  back  pressure. 

Purifying  Material. — Where  it  is  desirable  merely  to  remove 
from  the  gas  sulphureted  hydrogen,  oxide  of  iron  can  be  manu- 
factured cheaply  and  of  good  quality  as  follows:  A  large  quantity 
of  clean  gray  iron  borings,  free  from  steel,  brass,  and  other  metals, 
should  be  put  in  a  trough  similar  to  those  used  for  mixing  con- 
crete. To  every  500  Ibs.  of  these  borings  20  lbsv  say,  of  crys- 
tal rock  salt  may  be  added  and  the  whole  wet  down  by  throwing 
on  buckets  of  water  after  the  manner  of  slaking  lime.  The  mix- 
ture should  then  be  turned  with  a  fork  and  again  wet  daily,  all 
lumps  and  hard  particles  being  broken  up,  sifted,  or  thrown  aside, 
until  oxidation  is  complete.  It  may  then  be  mixed  with  clean 
shavings  containing  no  pine  rosin  or  other  gum,  at  the  ratio  of 
56  Ibs.  of  the  oxide  of  iron  to  a  bushel  of  the  mixture. 

In  those  instances  where  it  is  regarded  advantageous  to  re- 
move carbon  dioxide  from  the  gas  (in  regard  to  which  see  table 
on  Effect  of  CO2  on  Candle  Power),  lime  must  be  used  and  should 
be  slaked  after  the  following  manner :  A  layer  of  the  best  lime, 
say  5  in.  thick  and  unslaked,  should  be  evenly  spread  on  the 
floor  of  the  trough  as  described  above.  It  should  then  be  wet 
by  throwing  on  buckets  of  water.  At  no  time  should  a  hose  be 
used,  as  the  largest  possible  quantity  of  water  should  come  in 
contact  with  the  greatest  surface  of  lime  simultaneously.  Small 
jets  of  water  tend  to  slake  the  lime  unequally  and  to  make  it 
hard  and  full  of  lumps,  besides  causing  a  large  portion  to  be  burned 
out  and  inert. 

The  iron  borings  used  for  reduction  to  oxide  of  iron  may 
be  tested  by  passing  through  a  screen  with  a  mesh  not  greater 
than  J-  in.  Borings,  obtainable  from  the  average  machine-shop, 
are  coated  with  lard-oil,  or  other  grease  used  for  the  lubrication 
of  the  cutting-tool.  This  oily  coating  serves  as  an  insulation 
against  oxidation,  but  can  be  in  a  degree  overcome  by  the  mix- 
ture with  the  borings  of  unslaked  lime  before  their  wetting  with 
water  or  brine. 

Capacities  of  Purifiers. — In  purification  the  slowest  possible 
velocity  should  be  obtained  in  order  to  permit  time  for  chemical 
combination.  It  should  not  materially  exceed  £  in.  per  second, 
considering  the  box  empty.  The  purifying  material  generally 
occupies  about  three-fourths  of  the  contents  of  the  box,  leaving 
one-fourth  for  voids.  The  gas  will  therefore  actually  pass  through 
these  voids  at  a  velocity  of  about  f  in.  per  second. 

One  of  the  largest  gas-engineering  concerns  in  America  con- 
structs its  boxes  for  ordinary  conditions  upon  the  following  cal- 
culations: Taking  a  velocity  of  £  in.  per  second  for  the  area  of 


PURIFIERS.  75 

a  purifying-box  (which  is  equivalent  to  a  velocity  of  1440  ft. 
per  24  hours),  each  square  foot  of  purifying  area  can  purify  1440 
cu.  ft.  per  24  hours.  The  following  table  of  capacities  has  been 
figured  from  the  above  and  will  be  found  satisfactory  for  or- 
dinary conditions: 

Size  of  Boxes.  Approximate  Capacity  per  24  Hours. 

Feet.  Cubic  Feet. 

6X   8  70,000 

8X  8  92,000 

8X10  115,000 

8X12  138,000 

10X10  144,000- 

10X12  173,000 

12X12  207,000 

12X16  276,000 

16X16  369,000 

16X20  461,000 

20X20  576,000 

20X24  691,000 

24X24  828,000 

24X30  1,037,000 

30X30  1,296,000 

30X36  1,555,000 

The  above  capacities  are  for  ordinary  conditions  and  for 
proper  depth  of  purifying  material  when  oxide  is  used,  the  active 
oxide  being  between  four  and  five  feet  in  depth. 

It  will  be  noted  that  almost  all  the  empiric  formulse  given 
for  ridding  crude  gas  of  H2S  are  based  upon  coal-gas  purification, 
and  inasmuch  as  coal-gas  contains  from  400  to  800  grains  of  sul- 
phur compounds  and  carbureted  water-gas  contains  only  about 
10  to  15  grains  of  the  same  per  100  cubic  feet,  a  smaller  area  for 
purification  will  serve  in  the  case  of  water-gas  than  that  desig- 
nated by  old  authorities. 

Clegg's  rule  for  the  area  of  purifiers  was  1  ft.  area  for  every 
3600  cu.  ft.  made  per  day. 

Newbigging's  rule  for  the  area  of  purifiers  is:  The  maximum 
daily  make  multiplied  by  6  and  divided  by  1000  equals  the  num- 
ber of  square  feet  area  in  each  purifer. 

Anderson's  rule  for  lime  purifiers  was  that  the  rate  of  flow  of 
gas  through  the  purifier  should  not  exceed  2000  cu.  ft.  per  foot 
of  surface  per  24  hours. 

As  to  construction,  the  thickness  of  cast-iron  purifier  plates 
should  never  be  less  than  f  of  an  inch,  and  they  should  be  the 


76  AMERICAN  GAS-ENGINEERING  PRACTICE. 

best  quality  of  casting.  The  usual  width  is  5  ft.  Flanges  for 
bottom  plates  should  be  2 f  in.  by  f  in.  over  and  above  the  thick- 
ness of  the  plate.  Strong  brackets  should  be  fixed  under  each 
lute,  as  the  strain  is  greatest  at  this  point.  Larger  plates  than 
5  ft.  square  are  liable  to  warp  in  casting. 

The  depth  of  water-seal  in  purifiers  varies  from  12  in.  to  30  in., 
the  width  from  4£  in.  to  8  in.  As  a  matter  of  fact  the  seal  should 
never  be  less  than  18  in. 

A  formula  for  calculating  the  size  of  connections  on  purifiers 
is  as  follows:  Diameter  of  connections  in  inches  equals  the  square 
root  of  the  area  of  purifiers. 

The  economical  depth  of  oxide  seems  to  be  between  4  and 
5  ft.,  regardless  of  the  area  of  the  box. 

As  a  matter  of  fact  the  installation  of  purifiers  beyond  a  cer- 
tain extent  is  largely  a  matter  of  first  cost.  Where  it  is  practicable 
to  make  the  expenditure,  the  four-box  system,  having  a  center 
valve  by  which  any  combination  of  three  can  be  made,  is  most 
advantageous.  The  purification  of  gas  is  a  dual  process,  being 
partly  mechanical  and  partly  chemical.  For  example,  the  sulphur 
is  removed  by  chemical  union  with  the  oxide,  while  tar,  oil,  and 
condensation  are  removed  by  impinging  upon  the  purifying  mater 
rial.  It  is,  therefore,  a  marked  advantage  to  have  an  ample 
equipment  affording  sufficient  area  for  purification  and  at  the 
same  time  enabling  a  reserve,  so  that  while  one  box  is  thrown 
out,  the  balance  of  the  equipment  is  ample  to  carry  on  the  work. 
This  throwing  out  or  cleaning  should  be  done  in  rotation,  making 
connections  permitting  of  any  possible  combination  between  the 
boxes.  j 

In  passing  gas  already  purified  through  foul  oxide  it  is  pos- 
sible to  pick  up  impurities  in  transit,  such  as  CS2.  It  is,  there- 
fore, manifest  that  the  passage  of  the  gas  should  be  so  conducted 
as  to  pass  the  foul  gas  first  through  the  dirtiest  box,  or  that  least 
recently  cleaned.  It  should  then  pass  through  the  boxes  in  such 
order  as  to  leave  the  cleanest  box  last,  it  being  arranged,  if  pos- 
sible, that  the  last  box  in  the  series  be  kept  as  absolutely  clean 
as  practicable,  thereby  removing  from  the  gas  any  impurities 
which  may  remain  in  it  due  to  a  surcharge  or  a  lack  of  combining 
strength  of  the  oxide  in  the  preceding  boxes,  which  may,  possibly, 
have  passed  the  point  of  chemical  saturation. 

In  many  works  it  is  customary  of  late  years  to  build  concrete 
purifiers,  these  having  the  advantage  of  cheapness  and  extreme 
durability.  It  is  also  possible  to  build  these  out  of  doors,  thereby 
effecting  a  saving  of  floor-space  inside  the  works,  lessening  the  orig- 
inal cost  of  buildings,  etc.  These  boxes  are  not  as  convenient  for  the 
handling  of  purifying  materials  as  the  elevated  box.  High  boxes 


PURIFIERS.  77 

greatly  facilitate  the  labor  in  removing  and  replacing  the  oxide 
during  revivifying  where  the  in  situ  method  is  not  adopted,  as  they 
are  built  with  dumping-trays  and  cleaning  -valves  which  enable  the 
workmen  to  readily  drop  the  entire  contents  upon  the  floor  below. 
This  floor,  by  the  way,  should  be  either  of  concrete,  cement,  or 
brick,  by  reason  of  the  great  heat  attained  by  the  sulphur  in  the 
oxide  during  its  recombination  with  oxygen.  In  fact,  all  portions 
of  the  purifying-house  should  be  well  ventilated  and  as  nearly  as 
possible  fire-proof.  Nine-tenths  of  the  explosions  occurring  in  gas- 
works happen  in  this  department,  the  danger  being  greatly  dimin- 
ished where  there  is  free  ventilation,  and  where  any  gas  escaping 
through  blowing  -boxes,  evaporation  of  water  from  the  lutes,  leaks, 
etc.,  does  not  have  an  opportunity  to  collect  in  sufficient  quantities 
to  form  an  explosive  mixture.  Only  electric  incandescent  lights 
should  be  permitted  in  purifying-houses.  Where  they  can  be  used, 
reversing  valves  or  center  valves  are  unquestionably  of  great 
advantage  over  the  old  and  complicated  multiple-valve  system,  and 
will  be  found  a  great  economizer  of  space  and  time. 

Making  Oxide.  —  The  following  synopsis  of  purification  is  taken 
from  one  of  the  publications  of  the  Gas  Machinery  Co.  :  The  sesqui- 
hydroxide  of  iron,  Fe2(OH)6,  is  the  most  active  form  of  "  oxide," 
but  is  very  unstable,  decomposing  when  heated  to  about  100°  and 
forming  Fe2O3.3H2O.  This  last  compound  forms  the  most  active 
constituent  of  "oxide,"  combining  with  the  sulphureted  hydrogen 
in 


or 
Fe2O3.3H2O  +3H2S  =  2FeS  +S2  4-6H2O. 

The  bulk  of  the  sulphureted  hydrogen  is  absorbed  according 
to  the  first  equation,  probably  about  one-fifth  according  to  the 
second  equation. 

Various  methods  are  used  to  make  oxide,  the  principal  object 
being  in  every  case  to  obtain  the  ferric  oxide  in  as  fine  a  state  as 
possible  and  intimately  mixed  with  soft-wood  chips,  shavings,  or 
sawdust.  Pine  or  spruce  shavings  are  best,  as  they  contain  no 
objectionable  tannic  acid  found  in  oak,  poplar,  or  whitewood.  An 
oxide  should  always  be  alkaline. 

Method  1.  —  Mix  clean  fine  cast-iron  borings  with  sal-ammoniac 
in  proportion  of  20  Ibs.  to  1  oz.,  distribute  on  floor  in  layer  of  about 
6  inches,  and  allow  it  to  rest  for  at  least  three  weeks,  turning  and 
wetting  the  borings  every  few  days.  Mix  with  soft-wood  shavings 
or  chips,  previously  wetted  to  make  material  weigh  about  40  Ibs. 
per  cubic  foot. 


78  AMERICAN  GAS-ENGINEERING  PRACTICE. 

Method  2. — Mix  coarse  sawdust  or  small  chips  with  slaked  lime 
in  proportion  of  four  barrels  of  sawdust  to  one  of  lime.  Pour  cop- 
peras dissolved  by  steam  over  same,  using  about  9  pounds  of 
copperas  per  bushel  of  shavings.  Dissolve  1  Ib.  sal-ammoniac  in 
water  and  mix  with  20  Ibs.  of  iron  borings.  Then  mix  sawdust 
and  lime  with  borings. 

Method  3. — Spread  pine  shavings  in  a  layer  of  about  18  inches; 
cover  with  3  inches  of  previously  rusted  cast-iron  borings,  sprinkle 
with  salt  water  and  mix  thoroughly,  turning  over  every  day  for 
about  one  week. 

It  is  good  practice  in  the  manufacture  of  purifying  material  to 
mix  the  sawdust  or  shavings  with  the  iron  borings  prior  to  oxidiza- 
tion, so  that  the  iron  in  rusting  forms  a  coating  or  crust  upon  the 
shavings,  and  is  better  retained  in  the  material. 

Where  ground  cork  can  be  obtained  at  a  reasonable  price  it 
can  be  used  as  the  base  of  purifying  material  with  great  advantage 
over  shavings,  for  the  following  reasons:  It  does  not  become  soggy, 
cake,  pulverize  or,  owing  to  its  spongy  nature,  become  compressed 
as  do  other  materials,  thereby  greatly  relieving  the  back  pressure 
thrown  by  the  box;  its  back  pressure  is  only  one-third  that  of  the 
material  ordinarily  used.  As  50  per  cent,  more  oxide  can  be  mixed 
with  ground  cork  than  with  either  sawdust  or  shavings,  the  capacity 
of  the  box  is  increased  50  per  cent.  Cork  can  be  obtained  as  the 
waste  from  cork  factories,  and  although  the  initial  cost  is  invariably 
greater  than  sawdust  or  shavings,  it  is  sometimes  offset  by  its  other 
qualities. 

Ground  corn-cobs  are  also  in  use  as  a  substitute  for  cork,  and 
it  is  claimed  for  them  that  they  possess  nearly  if  not  all  of  the 
qualifications  possessed  by  cork.  Their  cheapness  is  a  great  recom- 
mendation in  their  favor.  The  following  table  gives  the  weights  of 
one  bushel  (2150  cubic  inches)  of  different  purifying  materials: 

Material.  Lbs.  per  Bushel. 

Pine  shavings 5 . 25 

Ground  cork 6 . 

Pine  sawdust 12 . 75 

Ground  corn-cobs 15. 

Iron  oxide.  : 112 . 

There  is  authority  for  the  statement  that  1.5  per  cent,  of  air 
admitted  to  the  purify  ing -boxes  with  the  gas  will  add  25  per  cent, 
to  the  purifying  capacity. 

Preparing  Lime. — Baker's  Masonry  Construction  gives  the  fol- 
lowing characteristics  for  good  mortar.  Lime:  1.  Freedom  from 
cinders  and  clinkers,  with  not  more  than  10  per  cent,  of  other  im- 


PURIFIERS.  79 

purities,  as  silica,  alumina,  etc.  2.  Chiefly  in  hard  lumps  with  but 
little  dust.  3.  Slakes  readily  in  water,  forming  a  very  fine,  smooth 
paste  without  any  residue.  4.  Dissolves  in  soft  water  when  this  is 
added  in  sufficient  quantities.  These  simple  tests  can  be  readily 
applied  to  any  sample  of  lime. 

Common  lime  is  a  substance  resulting  from  the  calcination  of 
pure,  or  nearly  pure,  limestones,  such  as  marble  or  chalk  at  a  high 
temperature,  applied  for  a  certain  time  to  drive  off  the  CO2  in  the 
limestone.  It  principally  has  calcic  oxide  with  3  to  10  per  cent,  of 
impurities,  silica  and  alumina,  magnesia,  oxide  of  manganese,  and 
trace  of  alkalies.  It  is  highly  caustic,  with  a  strong  affinity  for 
water,  rapidly  absorbing  about  one-fourth  of  its  own  weight,  which 
absorption  increases  its  temperature  to  an  intense  heat,  together 
with  an  increase  of  bulk  of  from  two  to  three  times  the  original 
volume.  This  reduction  to  an  impalpable  powder  is  called  "  slaked 
lime"  or  "calcic  hydrate,"  which  forms  with  water  an  unctuous 
paste.  This  paste,  in  common  with  mortar,  will  not  harden  in  the 
presence  of  water. 

The  advantage  of  using  lime  for  purification,  either  alone  or  in 
combination  with  iron  oxide,  is  the  more  complete  removal  from 
the  gas  of  sulphur  compounds  and  also  the  removal  of  carbonic 
acid,  for  which  the  oxide  alone  has  no  affinity  (see  table  of  Effect 
of  CO2  on  Candle  Power).  The  effect  of  CO2  on  illuminating  gas 
can  only  be  removed  entirely  by  purification.  Its  removal  causes 
a  whiter,  purer,  and  brighter  light,  which  cannot  be  compensated 
for  by  increased  enrichment  or  the  addition  of  hydrocarbons. 
These  advantages  may  be  worth  the  additional  cost  in  purification, 
even  where  lime  is  comparatively  dear. 

It  is,  however,  claimed  by  advocates  of  iron  oxide  that  Amer- 
ican coal-gas  contains  but  few  sulphurous  compounds  other  than 
sulphureted  hydrogen,  and  that  this  latter  is  the  only  needful 
impurity  to  remove,  and  can  be  accomplished  entirely  by  the  use 
of  oxide.  It  is  also  claimed  that  while  lime  removes  the  CO2  it 
also  mechanically  separates  from  the  gas  certain  of  the  heavier 
hydrocarbons,  thereby  neutralizing  the  benefit  derived  by  its 
removal. 

The  question  reduces  itself  largely  to  a  basis  of  cost  of  materials 
and  as  to  whether  additional  oil  be  used  to  make  up  the  loss,  or 
whether  a  saving  can  be  effected  by  the  removal  of  the  CO2, 
thereby  increasing  the  efficiency  of  a  less  amount  of  enrichment  used. 

Calculations. — As  to  the  purifying  capacity  of  lime  for  CO2, 
the  theory  is  as  follows:  Assuming  a  bushel  of  unslaked  lime  to 
weigh  80  Ibs.  and  to  contain  90  per  cent,  of  CaO,  one  bushel  of  lime 
would  therefore  contain  about  72  Ibs.  of  pure  CaO,  Slaking  this 
lime  the  following  reaction  would  take  place; 


80  AMERICAN  GAS-ENGINEERING  PRACTICE 

CaO  +  H2O=Ca(OH)2, 

or  calcic  hydrate.  Since  the  atomic  weight  of  Ca  is  40,  O  is  16, 
H  being  1,  the  equation  would  represent  (40  +  16)  +  (2+  16) 
=  (40  +  17X2)  =  74.  Therefore,  56  Ibs.  of  CaO  will  make  74  Ibs. 
of  Ca(OH)2,  and  72  Ibs.  of  CaO  will  make  95.11  Ibs.  of  Ca(OH)2. 
The  reaction  equation  between  slaked  lime  and  CO2  is 

Ca(OH)2  +  CO2  =  CaCO3  +  H2O 

74       +  44  =    100    +   18 

We  see  that  74  Ibs.  of  Ca(OH)2  will  combine  with  44  Ibs.  of  CO2, 
therefore  95.11  Ibs.  of  Ca(OH)2  will  combine  with  56.55  Ibs.  of 
CO2.  Dry  CO2  at  60°  F.  and  30  in.  barometer  weighs  1  Ib.  for 
each  8.595  cubic  feet,  so  that  56.55X8.595  =  486.047  cubic  feet. 

Supposing  gas  to  contain  3  per  cent,  of  C02  or  30  cubic 
feet  per  1000  cubic  feet  of  the  gas,  we  have  486.047  divided  by 
30,  or  16.202  cubic  feet  multiplied  by  1000,  equaling  16,202  cubic 
feet,  the  maximum  amount  of  gas  with  which  the  calcic  oxide  in 
one  bushel  of  lime,  as  aforesaid,  will  theoretically  combine.  Of 
course,  under  working  conditions,  this  combination  would  be 
exceedingly  less  complete. 

On  the  other  hand,  the  maximum  amount  of  sulphureted 
hydrogen  which  can  be  removed  from  gas  (theoretically)  can  be 
calculated  as  follows:  Suppose  a  bushel  of  the  purifying  material 
to  contain  an  amount  of  Fe2O3.H2O  equivalent  to  a  weight  of 
25  Ibs.  of  iron,  and  assuming  that  there  is  no  oxygen  present  in 
the  gas,  the  proportions  would  be  as  follows:  Of  the  Fe2O3.H2O 
the  atomic  weights  are  Fe  =  56,  O=16,  andH=l.  The  molecule 
of  the  oxide  will  therefore  contain  (56X2)  +  (16X3)  +  (1X2)  +  16 
=  178  parts  by  weight,  of  which  112  parts  are  iron  and  therefore 
25  Ibs.  of  iron  will  form  25X|if  =39.7  Ibs.  of  ferric  hydrate.  The 
reaction  given  by  Butterfield  for  the  removal  of  H2S  from  gas 
by  this  ferric  hydrate  is  as  follows: 


Fe2O3.H2O  +  3H2S  =  2FeS  +  S  +  4H20. 

The  proportion  between  Fe2O3.H2O  and  H2S  is  the  same  in 
both  equations;  the  amount  of  H2S  absorbed  by  a  given  quantity 
of  Fe2O3.H2O  is  the  same,  no  matter  which  of  the  two  above 
reactions  may  occur. 

The  atomic  weight  of  S  is  32;  therefore,  the  weight  of  H  being 


PURIFIERS.  81 

one,  the  molecule  H2SX3,  as  in  the  equation,  equals  3  (2X1  +  32), 
or  102  parts.  Therefore,  178  atomic  parts  of  Fe2O3.H2O  will 
combine  with  102  parts  of  H2S,  or  1  Ib.  will  combine  with  0.573 
Ibs.,  from  which  we  derive  that  39.7  Ibs.  of  Fe2O3.H2O  will  combine 
with  22.748  Ibs.  of  H2S.  Now,  if  1  Ib.  of  dry  H2S  at  60°  F.  and 
30  in.  barometer  occupied  a  volume  of  11.1229  cubic  feet,  we  con- 
clude that  22.748  Ibs.  will  correspond  with  22.748X11.1229, 
or  253.02  cubic  feet  of  H2ST 

Assuming  a  gas,  therefore,  to  contain  0.85  per  cent,  by  volume 
of  H2S  it  will  contain  8.5  cubic  feet  of  H2S  per  1000  cubic  feet  of 
gas,  or  253.02-^8.5  equals  29.791,  denoting  that  29.791  cubic  feet 
is  the  maximum  amount  of  gas  containing  the  said  amount  of 
H2S  that  can  be  theoretically  removed  by  chemical  union  with 
one  bushel  of  the  above-mentioned  purifying  material.  But, 
as  noted  in  the  calculations  for  the  theoretical  purifying  power 
of  lime,  these  results  cannot  be  nearly  attained  under  working 
conditions. 

Temperature. — It  may  be  noted,  however,  that  conditions  of 
temperature  have  much  to  do  with  the  combining  power  of 
both  the  lime  and  the  oxide,  as  at  a  temperature  below  30°  F. 
both  lime  and  ferric  oxide  are  practically  inactive  with  reference 
to  H2S,  and  abjve  this  temperature  their  capacities  for  com- 
bination increase  more  and  more,  until  at  a  temperature  of  100° 
to  120°  F.  the  action  becomes  as  complete  as  can  be  obtained 
under  working  conditions.  It  follows  from  this  that  purifying- 
houses,  lime-rooms,  and  revivifying-sheds  should  always  be  main- 
tained at  a  temperature  not  less  than  60°  F.,  and  that  concrete 
boxes  built  out  of  doors  and  other  exposed  purifiers  should  be 
properly  heated  with  steam-coil,  or  the  gas  itself  should  be  heated 
prior  to  entry  therein. 

Testing  Oxide  Boxes. — For  determining  whether  the  bed  of 
oxide  is  doing  service  or  not,  Fig.  16,  on  the  following  page,  illus- 
trates an  easy  method.  Byron  E.  Choller  describes  the  arrange- 
ment thus:  "It  frequently  happens  that  both  inlet  and  outlet 
of  a  purifying-bed  will  show  an  equally  foul  test  with  lead  paper, 
while  the  bed  may  yet  be  doing  work.  The  cut  shows  how  this 
condition  may  be  ascertained:  a  pipe  and  stop-cock  leading  from 
each  side  of  the  bed,  rubber  tubes  with  glass  nozzles  of  equal  size 
attached,  and  a  weak  solution  of  permanganate  of  potash  are  all 
that  are  required.  Put  equal  quantities  of  equal  strength  of  the 
solution  in  the  test-tubes,  insert  the  glass  tubes,  and  turn  on  the 
gas  in  both  at  the  same  time.  Foul  gas  will  make  the  solution 
clear  almost  immediately.  If  the  bed  is  doing  work,  the  inlet  side 
will  clear  up  quicker  than  the  outlet  side.  Two  or  three  grains, 
or  perhaps  less,  of  permanganate  of  potash  to  a  quart  of  clean 


82  AMERICAN  GAS-ENGINEERING  PRACTICE. 

water  is  sufficient.     Keep  the  solution  in  a  well-stoppered  bottle, 
and  do  not  make  up  too  much  at  a  time." 

Judging  from  a  few  experiments,  when  it  takes  the  outlet  four 
or  five  times  as  long  as  it  does  the  inlet  to  clear  up  by  this  method 
it  is  time  to  change  the  box,  as  in  such  case  it  would  be  taking 
out  only  about  20  per  cent,  of  the  sulphur  in  the  gas. 


SULPHUR  TEST  TI/5E, 

FIG.  16. — Comparison  of  Sulphur  in  Inlet  and  Outlet  Gas. 

Revivification. — This  can  be  done  while  the  gas  is  passing 
through  the  boxes  for  purification  by  admitting  a  small  percent- 
age of  air  or  oxygen,  ij  per  cent,  to  0.5  per  cent.,  with  the  gas; 
or  air  can  be  blown  or  sucked  through  the  foul  oxide  after  the 
box  is  turned  off  and  opened;  otherwise  the  oxide  can  be  re- 
moved from  the  box  and  revivified  elsewhere. 

By  revivification  is  meant  the  reduction  of  the  iron-sulphur 
compounds  again  to  active  iron  oxides  or  hydroxides;  reactions 
are 

2Fe2S3  +  3O2  -  2Fe2O3  +  3S2 


or 


12FeS  +9O2  +6Fe2O3  +6S2. 


PURIFIERS.  83 

Oxide  can  generally  be  used  until  it  has  taken  up  60  per 
cent,  of  sulphur  by  weight,  although  it  generally  becomes  fouled 
by  tar,  etc. ,  before  this  point  is  reached. 

As  to  the  proper  handling  of  oxide  for  revivification,  the 
Trustees  of  the  American  Gaslight  Association  have  to  say  as 
follows: 

"As  probably  no  two  samples  of  iron  oxide  (the  words  being 
used  to  denote  a  purifying  material  in  which  the  active  agent 
is  hydrated  ferric  oxide)  are  exactly  alike,  it  is  impossible  to 
lay  down  hard-and-fast  rules  that  will  apply  in  all  cases.  But 
there  is  one  truth  that  must  always  be  borne  in  mind  and  acted 
upon  to  secure  the  best  results;  this  is,  that  revivification  will 
be  the  more  rapid  and  complete  the  higher  (within  reasonable 
limits)  the  temperature  of  the  oxide.  Therefore,  the  treatment 
should  be  such  as  to  retain,  as  far  as  possible,  in  the  material 
all  the  heat  generated  by  the  chemical  action  that  occurs,  pro- 
vided, of  course,  that  this  heat  is  not  excessive. 

"At  a  works  using  oxide  purchased  from  three  different  firms, 
the  following  method  of  handling  during  revivification  was  found 
to  give  the  best  results:  As  the  oxide  was  removed  from  the  box 
it  was  thrown  on  to  the  re  vivify  ing -floor,  beneath  the  box,  into 
heaps,  each  about  8  feet  high,  and  allowed  to  remain  in  these 
heaps  until  it  was  thoroughly  heated,  the  length  of  time  required 
for  the  attainment  of  this  result  varying  from  one  to  two  hours 
for  fresh,  active  oxide  to  forty-nine  hours  or  more  for  that  nearly 
spent,  or  sluggish  from  any  other  causes.  When  hot  it  was  taken 
from  the  heap  and  placed  on  the  floor  in  long  ridges,  whose  cross- 
section  was  approximately  an  equilateral  triangle  with  24-inch 
sides.  Spaces  were  left  between  the  ridges,  and  as  the  oxide  on 
the  two  exposed  faces  revivified,  as  shown  by  its  change  in  color, 
it  was  scraped  down  into  these  spaces  until  the  whole  batch  was 
spread  out  in  a  layer,  with  a  uniform  depth  of  about  9  to  10  in. 
It  was  then  turned  over  with  shovels,  care  being  taken  to  have 
it  really  turned  and  the  material  that  had  been  on  the  bottom 
placed  on  top,  instead  of  the  whole  mass  being  merely  shoveled 
to  one  side,  which  is  very  often  all  that  the  so-called  turning  over 
amounts  to.  By  this  time  it  was  usually  thoroughly  revivified. 
If  not,  it  was  again  turned  over  as  often  as  necessary.  When 
revivified  the  batch  was  piled  in  a  heap  about  6  feet  high  and 
4  to  6  feet  wide  to  remain  until  it  was  put  back  into  the  box  in 
due  course.  Sufficient  time  was  allowed  to  elapse  between  each 
handling  for  complete  revivification  of  the  top  layer  of  oxide. 
During  the  operation  the  oxide  was  then  wet,  unless  it  became 
excessively  heated  or  so  dry  that  there  was  a  loss  and  a  nuisance 
in  handling,  owing  to  the  dust  arising  from  it.  By  thus  keeping 


84  AMERICAN  GAS-ENGINEERING  PRACTICE. 

the  oxide  as  dry  as  possible,  all  the  heat  produced  by  chemical 
action  was  made  available  for  maintaining  the  temperature  of 
the  material  and  thus  promoting  complete  revivification,  instead 
of  being  used  up  in  vaporizing  added  water. 

"In  handling  batches  of  fresh  oxide  care  must  be  taken  to 
prevent  their  becoming  so  highly  heated  as  to  ignite  the  sulphur 
and  shavings  contained  in  them.  Even  in  such  cases,  however, 
it  is  better  to  allow  the  oxide  to  stay  in  heaps.  Since  less  surface 
is  exposed  to  thp  air  in  this  way,  the  liability  of  ignition  is  less, 
and  if  it  does  occur  the  fire  can  be  more  readily  extinguished  by 
the  use  of  water.  Such  heaps  should  be  examined  at  frequent 
intervals  and  any  tendency  to  fire  be  attended  to.  Ignition  can- 
not occur  with  wet  oxide  until  the  water  has  been  practically 
all  evaporated,  so  wetting  the  oxide  will  always  prevent  it.  But 
as  it  also  retards  revivification  it  should  only  be  resorted  to  in 
cases  of  necessity.  Spreading  the  oxide  out  in  layers  and  turn- 
ing it  constantly  will  also  cool  it. 

"If  a  batch  of  oxide  does  not  heat  and  revivify  properly  when 
handled  as  above,  and  its  record  shows  that  it  is  not  yet  saturated 
with  sulphur,  it  can  sometimes  be  brought  into  good  condition 
again  by  being  exposed  out  of  doors  in  the  sun  during  the  warm 
weather,  the  sun  imparting  the  heat  necessary  to  start  and  main- 
tain the  revivification;  or  the  batch  can  be  heated  artificially. 

"Another  method  of  revivification  consists  in  placing  the 
oxide,  when  taken  from  the  heaps,  on  a  platform  of  purifier-trays, 
supported  about  a  foot  above  the  floor  of  the  revivifying-room 
in  such  a  way  as  to  permit  a  free  circulation  of  air  underneath 
the  whole  bed,  the  oxide  being  spread  in  a  layer  24  to  30  inches 
deep.  When  using  such  a  platform  revivification  takes  place  on 
the  bottom  as  well  as  at  the  top  of  the  layer,  proceeding  faster 
on  the  bottom.  When  the  batch  is  turned,  the  oxide,  still  foul, 
should  be  put  on  the  trays,  and  the  oxide  that  has  revivified 
either  piled  to  one  side  or  placed  on  top  of  the  foul  oxide.  If 
this  method  is  used  with  active  oxide  great  care  will  be  necessary 
to  prevent  firing,  as  revivification  proceeds  very  rapidly,  owing 
to  the  fact  that  ah*  passes  up  through  the  oxide  instead  of  merely 
being  in  contact  with  it." 

It  is  generally  the  custom  in  slaking  lime  at  works  to  reduce 
•  the  lime  to  a  sort  of  paste  which  will  neither  adhere  to  the  fingers 
when  suspended  from  them  nor  yet  fall  in  a  granular  powder. 
It  is  probable,  however,  that  this  is  hardly  sufficient  moisture, 
and  it  is  better  to  add  enough  water  to  bring  the  lime  to  a  homo- 
geneous mass.  This  mass  should  be  allowed  to  lie  over  some 
hours  and  then  be  worked  over  to  rid  it  from  lumps. 

The  tendency  of  all   gas-engineering    points  toward  revivifi- 


PURIFIERS. 


85 


cation  in  situ.  This  can  be  best  accomplished  by  the  admission 
of  air  in  a  fixed  ratio  (under  3  per  cent.)  with  the  gas  at  the  inlet 
of  the  purifiers,  which  is  easily  arranged  by  belting  a  forge-blower 


FIG.  17. — Revivifying  in  situ. 

or  one  of  the    Connelly  compressors  direct  to  the  shaft  of  the 
exhauster  (Fig.  17). 


LOSS   BY  IN 

SITU   PURIFICATION. 

Air  Admitted, 

Loss  in  Candle  Power, 

Per  Cent. 

Per  Cent. 

1.0 

2.0 

1.2 

2.3 

1.4 

2.6 

1.6 

3.0 

1.9 

3.6 

2.1 

3.9 

2.3 

4.3 

2.5 

4.8 

Removal  of  Traces. — It  must  be  noticed  in  all  forms  of 
purification  that  the  elimination  of  impurities,  being  chemical, 
can  occur  only  where  there  is  an  intimate  union  and  thorough 
contact  of  the  gas  with  the  material  used.  Should  any  tar  or 
oily  matter  be  allowed  to  come  in  contact  with  the  purifying 
material,  it  will  form  a  coating  or  insulation  which  will  tend  to 
prevent  chemical  action  from  taking  place,  besides  fouling  the 
material  and  causing  it  to  solidify  and  coke,  thereby  producing 
back  pressure.  It  is  of  enormous  advantage  to  remove  such 
substances  as  completely  as  possible  before  bringing  them  in 
contact  with  the  purifying  material,  to  which  end  the  gas  should 
first  be  passed  through  a  bed  of  shavings  or  coke-breeze  (oak- 
wood  shavings  should  never  be  used  for  any  purifying  purpose, 
because  of  the  tannic  acid  contained),  forming  a  filter,  which 


86  AMERICAN   GAS-ENGINEERING  PRACTICE. 

material  should  be  changed  immediately  as  soon  as  it  becomes 
saturated.  In  extreme  cases  a  P.  &  A.  condenser  may  be  used 
or  some  device  of  baffle-plates,  in  which  the  tar  and  oil  molecules 
carried  along  in  suspension  impinge  and  drain  away  by  gravity. 

Some  such  device  will  be  found  a  great  economy  in  works,  as 
it  has  been  the  experience  of  the  writer  from  a  number  of  tests 
that  the  oxide  or  lime  in  the  first  boxes  of  the  purifying  series 
almost  invariably  become  so  foul  as  to  become  useless  long  before 
its  combining  affinity  has  ceased,  and  that  by  the  use  of  proper 
extractors  or  filters  the  life  of  these  materials  will  be  indefinitely 
prolonged. 

In  addition  to  the  injury  done  purifying  material  by  small 
portions  of  heavy  tar  and  oil,  carried  over  in  suspense  by  the 
gas,  and  for  which  there  should  be  mechanical  separation,  tarry 
vapors  are  likewise  a  great  menace  not  only  to  the  material  itself, 
but  to  the  subsequent  features  of  distribution,  such  as  mains, 
services,  the  drums  of  meters,  the  cocks  of  fixtures,  and  espe- 
cially the  tips  of  burners  and  Welsbach  mantles  and  appliances. 

The  simplest  method  of  breaking  up  these  vapors  consists  in 
placing  a  layer  of  chips  and  shavings  or  coke-breeze  on  the  lowest 
tier  of  the  trays  of  each  purifying-box,  so  that  when  a  box  becomes 
the  first  in  the  series  the  gas  passes  through  this  filter,  and  the 
vapors  are  filtered  out  before  the  material  in  the  upper  portion  of 
the  box  is  reached.  It  is,  however,  better,  where  possible,  to  have 
one  box  or  other  vessel  retained  solely  for  the  use  of  such  scrubbing 
and  containing  several  thick  layers  of  wood  chips,  sawdust,  and 
shavings  or  breeze.  This  box  should  invariably  be  the  first  in 
the  purifying  series,  and  this  arrangement  has  the  advantage  that 
it  can  be  easily  determined  as  to  the  time  when  complete  satura- 
tion of  its  material  takes  place,  after  which  time  it  very  imper- 
fectly filters  out  the  passing  vapors.  A  discussion  of  the  subject 
will  be  found  in  the  Proceedings  of  the  American  Gaslight  Asso- 
ciation, Vol.  15,  pp.  142  to  147,  and  can  be  read  to  some  advantage. 

A  gas  is  said  to  be  saturated  with  vapor  at  a  certain  tempera- 
ture and  pressure  when  it  contains  the  full  amount  of  vapor  that 
it  can  carry  under  these  conditions.  Any  change  in  these  condi- 
tions will  change  its  point  of  saturation,  thereby  causing  it  to  carry 
more  or  less  vapor  or  moisture.  Also,  when  a  gas  is  so  saturated 
it  cannot  be  made  to  take  up  any  more  vapor  unless  these  condi- 
tions be  altered.  At  any  given  temperature  and  pressure  a  definite 
quantity  of  a  given  vapor  is  required  to  saturate  a  gas,  and  this 
quantity  is  invariably  the  same  under  the  same  conditions.  This 
is  called  the  saturation-  or  dew-point. 

Analysis  for  Total  Sulphur. — The  following  excellent  system 
was  described  before  the  American  Gaslight  Association  by  W.  B. 


PURIFIERS.  87 

Calkins  of  St.  Louis,  Mo.:  The  method  depends  upon  the  well- 
known  chemical  fact  that  sulphur  compounds,  such  as  carbon 
bisulphide,  mercaptan,  and  other  organic  forms,  break  up  and  form 
H2S  when  mixed  with  free  hydrogen  and  passed  over  heated 
platinized  asbestos  or  pumice. 

After  the  sulphur  compounds  have  been  changed  to  the  form 
of  H2S,  it  is  a  very  simple  matter  to  precipitate  the  sulphur  in 
some  form  easily  weighed  or  titrated,  and  the  per  cent,  of  sulphur 
figured  back  as  grains  of  total  sulphur  per  100  cubic  feet  of  gas. 

In  order  to  have  the  analysis  as  rapid  as  possible,  gravimetric 
methods  were  not  considered,  but  the  well-known  titration  method 
with  a  standard  iodine  solution  was  used. 

The  iodine  method  used  is  one  commonly  employed  for  rapid 
determination  of  sulphur  in  pig  iron  and  steel,  and  consists  in 
absorbing  or  precipitating  the  sulphur  evolved  from  the  iron  or 
steel  as  H2S  in  solutions  of  NaOH,  KOH,  or  in  an  ammoniacal 
solution  of  cadmium  or  zinc  chloride.  The  use  of  the  two  latter 
are  to  be  preferred  on  account  of  the  sulphur  being  in  a  visible 
form  (CdS  or  ZnS),  and  one  which  is  not  liable  to  alteration  on 
standing. 

The  reaction  that  takes  place  when  H2S  is  run  into  a  strongly 
ammoniacal  solution  of  cadmium  chloride  is  as  follows  : 

H2S  +  CdCl2  +  2NH4OH  =  CdS  +  2NH4C1  +  2H20. 

Now  if  the  solution  containing  the  precipitate  of  CdS  is  diluted 
with  a  large  volume  of  cold,  distilled  water  and  a  sufficient  quantity 
of  HC1  added,  H2S  is  set  free  by  the  following  reactions: 


A  considerable  excess  of  HC1  is  needed  to  effect  a  complete 
reaction,  and  the  volume  of  water  present  must  be  large  and  cold 
in  order  to  prevent  the  escape  of  any  H2S. 

The  solution  of  H2S  in  water  is  now  titrated  with  a  standard 
iodine  solution,  using  a  little  fresh  starch  solution  as  an  indicator; 
the  reaction  is  as  follows: 

H2S  +  2I  =  2HI+S. 

The  least  excess  of  iodine  is  shown  by  the  intense  blue  color 
(iodide  of  starch)  that  is  instantly  formed  as  soon  as  the  reaction 
is  complete.  The  solutions  needed  are  a  standard  solution  of 
iodine,  a  fresh,  clear  solution  of  starch,  and  a  strongly  ammoniacal 
solution  of  cadmium  or  zinc  chloride. 


88  AMERICAN  GAS-ENGINEERING  PRACTICE. 

No  arbitrary  standard  solution  of  iodine  is  needed,  but  one  can 
be  made  up  and  standardized  to  suit  local  conditions,  the  prepara- 
tion and  standardizing  of  which  can  be  found  fully  explained  in 
any  good  book  on  quantitative  analysis. 

For  the  cadmium  chloride  solution  a  good  strength  for  the 
stock  bottle  is  made  by  dissolving  four  grains  of  cadmium  chloride 
in  100  c.c.  of  water,  and  when  dissolved  add  an  equal  volume  of 
strong,  chemically  pure  ammonia. 

The  platinized  asbestos  for  filling  the  combustion-tube  is  easily 
prepared:  Take  J  pound  of  clean  asbestos  wool,  free  from  sulphur, 
wash  in  2  ounces  of  a  5  per  cent,  solution  of  platinum  chloride, 
then  dry,  place  in  a  large  evaporating,  dish,  separate  the  wool, 
moisten  evenly  with  alcohol  and  ignite  ;Ythis  forms  a  coating  of 
platinum  black  over  the  wool  fibers.  The  wool  must  now  be 
strongly  heated  in  order  to  drive  off  any  free  acid. 

The  apparatus  needed  for  this  method  consists  in  a  good  meter, 
on  3  that  will  accurately  measure  -^  of  a  cubic  foot  (or,  in  place  of 
this,  a  good  meter-prover  can  be  used,  and  the  sample  of  gas  it 
contains  can  be  taken  as  representing  the  average  gas  made  for 
several  hours);  a  small  15-burner  combustion  furnace;  some  good 
Jena  glass  combustion-tubing  30  in.  long,  or  a  flanged  porcelain 
tube  glazed  inside,  30  in.  long  and  J  in.  inside  diameter;  about 
four  plain,  ringed-neck  glass  cylinders  9  in.  high,  to  hold  about 
150  c.c. ,  with  2-holed  rubber  stoppers  to  fit;  one  small  brass  aspira- 
tor^ filter-pump,  and  several  feet  of  good  glass  and  pure  gum  rubber 
tubing  for  making  connections. 


FIG.  18. — Analysis  for  Total  Sulphur  Apparatus. 

Before  starting  the  test  the  meter  and  combustion-tube  must 
be  filled  full  of  the  gas  to  be  tested  and  the  gas  shut  off,  then  the 
combustion  furnace  heated  up,  slowly  at  first  so  as  not  to  crack 
the  combustion-tube,  until  the  tube  is  a  dull  red  (about  1000°  to 
1200°) ;  now  read  the  meter,  turn  on  the  gas,  and  by  means  of  the 
aspirating-pump  draw  the  gas  through  the  loosely  packed  combus- 
tion-tube, which  is  connected  to  a  delivery-tube  which  reaches 
almost  to  the  bottom  of  the  first  receiving  cylinder,  then  through 
a  second  receiving  cylinder  and  out  through  the  aspirating-pump, 


PURIFIERS.  89 

which  is  attached  to  the  water  service.  By  means  of  the  pump 
the  gas  can  'be  drawn  at  any  required  speed  through  the  apparatus, 
but  faster  than  J  foot  an  hour  is  liable  to  bubble  the  cadmium 
chloride  solution  out  of  the  first  cylinder  into  the  second.  The 
second  cylinder  is  used  as  a  guard  in  case  any  H2S  might  pass  the 
first  one. 

Both  cylinders  are  filled  with  a  solution  of  the  same  strength; 
3  c.c.  of  the  strong  cadmium  solution  is  first  added  to  each  cylinder, 
then  about  10  c.c.  of  strong  ammonia,  after  which  the  cylinders 
are  filled  with  distilled  water  to  a  depth  of  about  7  in. 

When  the  required  volume  of  gas  has  been  passed,  the  meter 
and  aspirating-pump  are  shut  off,  the  cylinders  disconnected  and 
washed  out  with  a  large  volume  of  cold  water  into  a  deep  cylin- 
drical beaker,  a  few  cubic  centimeters  of  starch  solution  are  added, 
and  then  a  large  excess  of  concentrated  chemically  pure  HC1,  and, 
without  much  stirring  at  first,  the  whole  titrated  with  the  iodine 
solution  as  rapidly  as  possible,  adding  it  until  the  last  drop  changes 
the  opalescent  liquid  to  a  deep  blue,  not  disappearing  on  standing 
for  two  or  three  minutes. 

There  must  be  no  delay  in  titrating,  for  if  the  solution  contain- 
ing the  CdS  is  allowed  to  stand  it  will  lose  £[28,  or  the  sulphide  may 
oxidize. 

Another  method  is  to  quickly  filter  off  the  flocculent  precipi- 
tated CdS,  the  filter  and  precipitate  placed  in  a  deep  beaker  con- 
taining a  large  volume  of  cold  water,  the  HC1  and  starch  solu- 
tions added,  then  titrating.  This  avoids  the  presence  of  a  large 
amount  of  ammonia  salts  and  any  hydrocarbons  absorbed  in 
the  liquid  with  which  it  has  been  claimed  the  iodine  reacts 
slightly. 

The  combustion-tube  must  be  loosely  packed  from  time  to 
time  with  fresh  platinized  asbestos,  for  the  old  will  gradually  be 
coated  with  carbon  and  the  tube  stopped  up. 

To  prove  that  the  chemical  reaction  was  complete,  known 
quantities  of  chemically  pure  carbon  bisulphide  and  mercaptan 
were  vaporized  with  pure  hydrogen  gas.  This  mixture  was 
passed  through  the  apparatus,  the  H^S  precipitated  with 
cadmium  chloride,  and  the  amount  of  sulphur  found  agreed 
with  the  per  cent,  of  sulphur  contained  in  the  organic  sulphur 
compounds. 

Other  tests  for  accuracy  were  made  by  comparing  results 
obtained  from  the  same  sample  of  gas,  by  determining  the  per 
cent,  of  total  sulphur  present,  first  with  the  London  Gas  Referees' 
sulphur  apparatus,  then  by  the  combustion  method,  and  the 
results  agree  very  closely.  The  following  are  a  few  of  the 
results : 


90 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


SULPHUR   IN   GAS    PER   ONE   HUNDRED    CUBIC   FEET. 

Referees'  Combustion 

Method.  Method. 

1 14.512      14.530 

2 16.224      16.320 

3 15.820      15.980 

4 18.256      18.724 

f 

Correction  for  temperature  and  pressure  must  be  made  as  in 
any  gas  analysis. 


...-,.,... ^-.v 


SecT,e»N  CO 

B 


PURIFIERS. 


91 


nt     a, 


E 

FIG.  20. 

The  accompanying  cuts.  A,  B,  C,  D  (Figs.  19  and  20),  show  the  arrangement 
of  a  Purifying-box  equipped  with  the  Jaeger  Grid,  while  cut  E  shows  a  section  of 
the  Grid  itself.  AS  will  be  seen  the  object  of  the  Grid  is  to  increase  the  inti- 
macy of  the  circulation,  and  obtain  for  the  box  higher  cubical  capacity  and 
greater  oxide  efficiency. 


CHAPTER  VIII. 
EXHAUSTERS. 

THE  trustees  of  the  American  Gaslight  Association  give  the 
following  calculation  for  obtaining  the  horse-power  necessary  to 
handle  a  given  quantity  of  gas,  pumping  it  with  an  exhauster. 
As  an  example  of  their  calculation,  they  take  the  pumping  of 
17,000  cubic  feet  of  gas  per  hour,  with  an  inlet  pressure  of  1.1  in. 
against  an  outlet  pressure  or  head  of  12  in. 

"  Power  Required. — The  term  horse-power  is  used  to  indicate 
the  rate  at  which  mechanical  work  is  done  and  denotes  the  per- 
formance of  33,000  foot-pounds  of  work  per  minute;  that  is,  the 
raising  of  a  weight  of  33,000  pounds  through  a  height  of  one  foot, 
or  the  overcoming  of  a  resistance  of  33,000  pounds  through  a 
space  of  one  foot.  The  horse-power  required  to  pump  gas  can 
therefore  be  calculated  by  dividing  the  product  of  the  resistance 
overcome  and  the  space  through  which  it  is  overcome  in  a  minute 
by  33,000,  the  resistance  being  measured  in  pounds  pressure  and 
the  space  in  feet.  The  resistance  is  determined  by  the  net  pres- 
sure against  which  the  exhauster  is  working,  that  is,  by  the  differ- 
ence between  the  pressure  at  the  outlet  and  that  at  the  inlet  of 
the  exhauster.  The  space  can  be  taken  as  the  number  of  cubic 
feet  of  gas  pumped  in  a  minute,  without  any  reference  to  the  actual 
velocity  with  which  the  gas  passes  through  the  outlet-pipe,  since 
with  a  given  outlet  pressure  the  total  resistance  against  which 
the  exhauster  is  working  varies  directly  as  the  area  of  the  out- 
let-pipe, while  the  velocity  of  the  gas,  or  the  space  passed  through 
in  the  unit  of  time,  varies  (when  the  same  quantity  is  pumped 
per  minute)  inversely  as  the  area  of  the  outlet-pipe,  and  there- 
fore the  product  of  the  total  resistance  and  the  space  passed 
through  will  always  be  equal  to  the  product  obtained  by  mul- 
tiplying the  resistance  per  square  foot  by  the  number  of  cubic 
feet  of  gas  pumped  in  the  unit  of  time.  The  gas  pressure  is  usu- 
ally given  in  terms  of  the  height  in  inches  of  the  water  column 
which  it  will  balance;  to  convert  this  to  pounds  per  square  foot, 

92 


EXHAUSTERS.  93 

it  is  necessary  to  multiply  it  by  the  weight-  of  a  column  01  water 
1  sq.  ft.  in  area  and  1  in.  high.  A  cubic  foot  of  water  weighs 
62.5  pounds;  therefore  a  column  of  water  12  in.  high  exerts  a 
pressure  of  62.5  pounds  per  sq.  ft.,  and  a  column  1  in.  high  will 
exert  a  pressure  62.5 -=-12  =5. 2  pounds  per  sq.  ft.  The  horse- 
power required  for  the  actual  work  of  pumping  the  gas  can  there- 
fore be  determined  by  multiplying  the  number  of  cubic  feet 
pumped  per  minute  by  the  product  obtained  by  multiplying  the 
net  pressure  in  inches  of  water  by  5.2  (which  gives  the  pressure 
in  pounds  per  square  foot  against  which  the  exhauster  is  work- 
ing) and  dividing  the  final  product  by  33,000.  Putting  this  rule 
into  the  shape  of  a  formula,  we  have 


33,000  ' 

in  which  V= number  of  cubic  feet  of  gas  pumped  per  minute,  and 
H  =  thQ  difference  between  the  outlet  and  the  inlet  pres- 
sure in  inches  of  water. 
In  the  present  problem 

17.000  - 

-^-  =  283.33  cu.  ft., 

and 

#  =  12-0.1  =  11.9  in., 

283.33X11.9X5.2 


33,UUU 
17532.46 


33,000 


-0.531  h.p. 


"  Therefore  the  horse-power  required  for  pumping  the  gas, 
without  taking  into  consideration  the  friction  of  the  exhauster 
or  any  other  losses  of  power  in  the  machinery,  is  0.558  h.p. 

"  George  J.  Roberts,  from  actual  tests  on  pumping  gas  into  a 
holder,  deduced  the  following  formula  for  an  exhauster  of  the 
\Vilbraham  type: 

H.P.  =0.00511#7; 

H  =  the  net  pressure  in  inches  pumped  against,  and 
V= thousands  of  cubic  feet  pumped  per  hour. 

"  Substituting  the  value  of  H  and  V  in  the  present  problem, 
we  have 

H.P.=0.00511X11.9X17  =  1.03. 


94  AMERICAN  GAS-ENGINEERING  PRACTICE. 

"  So  that  the  total  horse-power  required  according  to  this  for- 
mula is  nearly  double  that  required  for  pumping  the  gas."  Or, 
in  other  words,  the  efficiency  of  the  engine  and  exhauster  when 
working  at  this  rate  is  only  about  50  per  cent. 

Installation. — In  installing  the  exhauster,  solid  masonry  should 
invariably  be  used,  no  other  material  being  as  good  for  a  founda- 
tion. The  bed-plate  is  bolted  directly  by  bed-bolts  to  this,  and 
without  any  intervening  wooden  structure,  which  may  have  a 
tendency  to  decay  and  increase  vibration.  One  of  the  most 
common  causes  of  trouble  is  due  to  the  springing  of  the  outlet 
and  inlet  connections  into  place  to  correct  the  fitting,  the  latter 
not  being  true.  This  tension  has  a  tendency  toward  causing  knock- 
ing and  binding  of  the  working  parts  of  the  machine.  The  con- 
nections should  invariably  be  square  and  true,  and  so  supported 
as  to  relieve  the  flanges  of  the  exhauster  not  only  of  any  torsion, 
but  of  their  own  weight. 

Internal  heating,  which  is  difficult  to  discover,  occasioned  by 
the  thrust  of  the  crank-shaft  of  the  engine,  is  another  contin- 
gency with  exhausters.  This  is  frequently  caused  by  the  set 
of  the  machine  not  being  perfectly  level  and  can  usually  be  de- 
tected and  the  cause  located  by  taking  out  the  bolts  of  the  coup- 
ling, an  imperfect  alignment  being  indicated  by  the  springing 
of  the  coupling  flanges.  Misalignment  of  the  parts  of  the  bed- 
plate is  indicated  by  a  separation  of  these  parts,  while  a  thrust 
of  the  crank-shaft  is  shown  by  the  binding  of  the  flanges  against 
each  other.  This  can  be  remedied  by  forcing  the  engine  to  or 
from  the  exhauster,  re-reaming  the  dowel-holes  and  driving  in 
fresh  dowels. 

Operation. — It  sometimes  happens,  after  an  exhauster  is  shut 
down,  that  it  is  " tar-bound."  This  is  overcome  by  the  intro- 
duction of  benzine  or  kerosene  through  the  sight-feed  oilers, 
placed  at  the  top  of  the  exhauster  case. 

An  exhauster  should  be  as  carefully  kept  up  as  any  other 
form  of  a  steam-engine.  The  first  and  most  important  point 
is  that  of  cleanliness,  which  cannot  be  overrated,  all  excess  of 
tar,  oil,  and  dirt  being  kept  away  from  the  governor  and  other 
working  parts.  The  adjustments  should  be  examined  daily,  and 
once  or  twice  a  season  an  indicator  diagram  should  be  taken 
from  the  engine,  to  note  if  valves  are  properly  set.  The  machine 
should  have  constant  attention  with  regard  to  oiling,  and  the 
engineer  should  by  regular  inspection  note  that  the  oil-cups  are 
replenished  and  are  emptying  equally.  The  packing  of  ex- 
hausters is  especially  prone  to  become  hard  and  to  grind  the 
axle-shafts  and  other  working  parts.  It  should  be  removed  as 
often  as  inspection  shows  to  be  necessary,  perhaps  once  in  three 


EXHAUSTERS.  95 

months.  It  is  needless  to  say  that  all  bearings  must  be  prop- 
erly kept  up,  especially  those  supporting  the  impellers.  The 
gears  may  best  be  lubricated  with  a  mixture  of  grease  of  good 
quality  or  graphite. 

Losses. — The  power  lost  in  friction  in  an  exhauster  will  aver- 
age between  7  and  9  per  cent,  of  the  total  amount  applied  to  the 
machine  during  the  period  of  full  load.  It  is,  however,  very 
nearly  constant  and  varies  but  slightly  between  the  maximum 
and  minimum  load.  The  slip  is  also  a  constant  quantity  under 
any  one  pressure,  the  total  slip  per  minute  being  about  the 
same,  whether  the  machine  is  running  fast  or  slow.  In  a  com- 
parative test,  where  the  air  delivered  was  measured  by  meter, 
and  in  what  is  known  as  the  " closed  discharge  test,"  the  results 
disclosed  little  or  no  discrepancy.  The  "  closed  discharge  test " 
is  apparently  the  more  accurate,  and  consists  in  closing  the  valve 
on  the  discharge  side  of  the  machine,  when  the  machine  is 
then  operated  at  such  speed  as  to  maintain  the  pressure  desired. 
The  slip  is  then  equal  to  the  displacement  of  the  machine  per 
revolution,  multiplied  by  the  number  of  revolutions  per  minute, 
to  maintain  the  pressure.  It  is,  of  course,  understood  that  the 
valves  in  the  connection  should  be  perfectly  tight. 

As  to  thermal  loss,  there  is  but  little  known.  Air  compressed 
to  three  pounds,  according  to  the  test  of  Geo.  C.  Hicks,  Jr.,  shows 
an  increase  in  temperature  of  18  deg.  F.  The  specific  heat  at 
constant  pressure  is  about  0.2377;  hence  it  will  appear  that  the 
loss  would  be  extremely  small  in  actual  units  of  work.  For  in- 
stance, the  maximum  loss,  due  to  the  difference  between  iso- 
thermal and  adiabatic  compression  in  air  compressed  to  five 
pounds,  is  only  about  4.5  per  cent.  In  the  case  of  the  rotary 
machine,  at  least,  the  compression  is  adiabatic  or  very  nearly  so. 

Where  the  steam-piping  is  small,  or  the  steam  pressure  vari- 
able, it  is  advisable  to  interpose  a  regulating-valve  immediately 
before  the  steam-inlet  of  the  exhauster. 

In  the  use  of  any  positive-pressure  gas-pump  (especially  where 
there  is  no  holder  on  the  line)  and  in  the  connections  of  an  ex- 
hauster, a  relief-valve  or  seal-pot  should  be  placed  upon  the  pressure 
side,  its  overflow  or  " escape"  being  connected  to  a  blow-back  or 
by-pass,  leading  into  one  of  the  holders  or  the  suction  side  of 
the  pump  or  exhauster. 

In  the  first  case  this  is  to  prevent  excessive  " building  up"  of 
pressure  in  the  pipe-line;  in  the  case  of  the  latter,  or  exhauster, 
the  arrangement  is  to  prevent  the  "blowing"  of  the  purifying- 
boxes;  in  this  instance  the  relief -valve  or  seal  for  blow-back  must 
be  adjusted  considerably  under  the  seal  capacity  of  the  boxes, 
securing  thereby  a  margin  of  safety. 


96 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


Few  engineers  are  aware  of  the  loss,  amounting  to  a  material 
item,  occurring  through  the  blowing  of  the  boxes  and  the  conse- 
quent escape  and  loss  of  gas,  to  say  nothing  of  the  tremendous 
danger  to  life  and  property. 

Slip. — According  to  Mr.  Geo.  C.  Hicks,  Jr.,  "the  slip  of  a  ro- 
tary blower  should  vary  as  the  square  root  of  the  pressure,  speed 

being  constant,  and  inversely  as  the 
speed,  the  pressure  being  constant; 
directly  as  the  clearance;  directly  as 
the  square  root  of  the  reciprocal  of 
the  specific  gravity,  and  directly  as 
the  square  root  of  the  ratio  of  the 
absolute  temperatures." 

For  continuous-contact  impellers 
the  law  of  flow  of  gas  through  an 
orifice  is  very  close  to  actual  results. 
It  will,  therefore,  appear  that  to  at- 
tain high  efficiency  in  a  machine  it 
should  be  as  nearly  as  possible  of  such 
size  as  will  warrant  approximately  its 
maximum  rate  of  speed  during  service. 
For  the  increase  of  volume  of  gas 
passed  in  a  given  time  decreases  the 
per  cent,  of  slip  in  inverse  ratio  as 
the  increase  of  revolutions  per  min- 

FIG    21   -  Exhauster    By-pass  ut?'     Thif  !?  ?enerally  true  UP  to  the 
and  Connections.  safe  speed  limit. 

The  slip  also  varies  directly  as  the 

square  inches  of  the  opening  of  clearance,  which  should  therefore 
be  kept  down  to  the  lowest  margin  compatible  with  safety.  This 
is  especially  true  with  heavy-duty  exhausters  (operating  over  3 
to  4  Ibs.  pressure). 

In  low-pressure  work  the  slip  may  be  said  to  vary,  inversely 
with  the  speed,  from  1  to  20  per  cent.  Temperature  affects  the 
slip  only,  as  has  been  stated,  as  proportional  to  the  square  root 
of  the  ratio  of  absolute  temperature,  and  has  nothing  to  do  with 
the  shrinkage  in  volume  due  to  a  decrease  in  gas  temperature. 

Specific  gravity  affects  the  slip,  as  above  stated,  as  the  square 
root  of  the  reciprocal,  as,  for  instance,  gas  at  0.5  gravity  would 
give  a  slip  1.41  times  as  much  as  air  under  similar  conditions. 

The  friction  losses  in  an  exhauster  are  practically  those  en- 
tailed by  the  bearings  and  the  gears. 

The  pressure  of  the  gears  should  be  plus  in  a  downward  direc- 
tion, in  order  to  prevent  a  "floating  shaft,"  as  such  an  arrange- 
ment is  hard  to  keep  in  alignment  and  tends  toward  hot  bearings. 


EXHAUSTERS.  97 

In  this  connection  we  may  say  that  much  depends  upon  the 
accuracy  of  cutting  and  keying  of  the  impeller-gears,  the  juxta- 
position of  the  impellers,  the  conditions  of  clearance,  and  the 
general  alignment  subject  to  such  accuracy.  For  low-pressure 
machines  (1  to  2  Ibs.)  single  gears  with  double  outboard  bearings 
are  preferable,  while  with  the  heavy-duty  machines  double  gears 
with  outboard  bearings  give  better  satisfaction.  The  advantage 
of  the  outboard  bearing  is  to  distribute  the  strain  upon  the  machine 
and  furnish  double-  instead  of  single-bearing  surface,  besides 
stiffening  the  entire  apparatus. 

Horizontal  machines  are,  moreover,  stiffer  and  better  adapted  to 
heavy  duty  than  the  vertical  type.  The  double  outboard  bearings 
mentioned  should  be  invariably  specified,  their  cases  in  the  instance 
of  high  pressures  being  approximately  2.25  times  the  gear  diameter 
in  length,  and  a  bore,  say,  1.65  times  the  gear  diameter;  for  light 
duty  (say  1  or  2  Ibs.)  1.5  times  the  gear  diameter  will  be  sufficient. 

The  driving  of  exhausters  belongs  to  three  classes,  viz.,  belt 
or  rope  drive,  pinion  gear  and  silent  chain,  and  "  direct  connec- 
tion." For  the  first  the  belt  pull  should  average  about  75  Ibs. 
and  have  a  speed  of  between  3000  and  4000  feet  per  minute.  At 
this  figure  the  loss  of  power  should  not  exceed  over  3  per  cent. 
Counterbelting  should  be  permitted  only  on  very  light  service  loads. 
For  this  class  of  drive  outboard  bearings  are  especially  ne3essary 
to  maintain  rigidity. 

The  silent  chain  should  give  an  efficiency  of  about  98  per  cent., 
gear  transmission  95  per  cent.  These  methods  are  especially 
necessary  in  connection  with  turbine  or  high-speed  motive  power. 

Where  direct  connection  is  used  the  flexible  connection  is 
decidedly  advisable,  and  is  absolutely  essential  in  heavy-duty 
machines  having  the  service  of  over  4  Ibs.  This  is  by  reason  of  the 
facility  with  which  alignment  between  the  exhauster  and  prime 
mover  may  be  maintained,  this  being  almost  impossible  where 
the  connection  is  rigid. 

Of  late  years  small  exhausters  have  come  into  frequent  use 
in  connection  with  " booster"  or  high-pressure  feed-lines,  also 
for  long-distance  transmission. 

Such  service  rarely  exceeds  a  maximum  of  over  4  Ibs.  dis- 
charge duty  with  8  to  12  inches  water  pressure  on  the  suction 
end.  Under  such  conditions  the  total  losses  (principally  slip  and 
friction)  will  hardly  exceed  a  maximum  of  15  per  cent.,  7  or  8 
per  cent,  being  the  average.  As  this  service  must  be  executed 
under  variable  conditions  of  speed,  the  prime  mover  should  be 
designed  for  very  sympathetic  hand  regulation. 

The  highest  efficiency  of  this  service  is  at  about  5  Ibs.  duty, 
where  the  minimum  efficiency  is  possibly  not  below  80  per  cent. 


98  AMERICAN  GAS-ENGINEERING  PRACTICE. 

For  heavier  duty,  however,  say  8  to  10  Ibs.  or  over,  its  commer- 
cial efficiency  ceases,  and  some  other  form  of  condenser  or  pump 
should  be  used.  In  emergency,  however,  for  service  of  this  kind 
two  or  more  exhausters  may  be  connected  in  tandem  with  a  fair 
degree  of  efficiency. 

In  summing  up  the  losses  due  to  slip,  Mr.  Geo.  C.  Hicks,  Jr., 
an  expert  in  the  matter,  says : 

" Losses  due  to  slip  are  dependent  on  two  principal  factors, 
pressure  and  speed.  The  curves  shown  for  constant  speed  and 
varying  pressure  cover  a  range  of  pressure  from  22  in.  of  water 
to  122.1  and  a  loss  due  to  slip  within  the  ranges  of  ordinary  opera- 
tion of  from  30  per  cent,  maximum  to  1  per  cent,  minimum. 

"In  gas-exhauster  work,  say  at  a  maximum  pressure  of  22.5 
in.  of  water,  the  slip  ranges  from  1  per  cent,  for  various  speeds 
on  an  air  basis.  Modifying  this  for  gas  by  multiplying  by  the 
square  root  of  the  reciprocal  of  the  specific  gravity  or  1.41,  the 
resultant  loss  is  from  1.41  per  cent,  to  28  per  cent.,  or  an  average 
slip  of  14.75  per  cent,  for  speeds  ranging  from  50  to  170  r.p.m. 

"  For  pumping  clean  gas,  where  it  is  possible  to  use  a  nearly 
constant  speed,  it  is  clearly  advisable  to  select  a  machine  to  oper- 
ate at  its  highest  safe  speed  and  thus  get  an  efficiency  of  81  per 
cent,  according  to  these  tests,  which  were  made  on  a  machine 
not  specially  built  for  this  service.  Later  results  show  an  effi- 
ciency of  85  per  cent,  under  5  Ibs.  pressure.  The  loss  due  to 
friction  ranges  from  1  to  15.5  per  cent,  and  shows  an  aver- 
age of  about  7  per  cent,  at  130  and  170  r.p.m.,  and  5.4  per  cent, 
at  110  r.p.m.;  so  it  is  safe  to  assume  7  per  cent,  as  an  average 
friction  load.  This  gives  for  gas-exhauster  work  an  average 
efficiency  of  power  applied  to  the  shaft  of  85.26  per  cent,  times 
93  per  cent.,  or  nearly  80  per  cent.,  as  the  useful  effort  of  the  power 
applied  to  the  shaft.  For  high-pressure  pumping  we  have  81  per 
cent,  multiplied  by  93  per  cent.,  or  75.3  total,  and  on  a  basis  of 
85  per  cent,  volumetric  efficiency  a  total  efficiency  of  80  per  cent. 
The  loss  due  to  temperature  is  not  chargeable  to  the  machine 
construction,  as  it  is  simply  a  shrinkage  proposition  and  brings 
one  to  much  the  same  set  of  formulas  as  those  used  in  estimating 
condenser  surfaces.  Not  considering  the  latent  heat  of  the  vapors, 
an  approximate  method  is  to  consider  the  volumes  as  propor- 
tional to  their  absolute  temperatures. 

"The  increased  slip,  as  stated  before,  would  be  proportional 
to  the  square  root  of  the  ratio  of  the  absolute  temperature.  As- 
suming a  rise  to  140  deg.  from  60  deg.,  the  slip  would  be  multi- 
plied by  the  ratio  1.07;  this  14  per  cent,  slip  times  1.07  equals 
about  15  per  cent.,  or  an  increase  of  only  1  per  cent,  due  to  a  rise 
in  temperature  of  80  deg.  The  heat  of  compression  at  10  Ibs. 


EXHAUSTERS.  99 

would  raise  air  at  60  deg.  up  to  145,  affecting  the  slip  about  the 
same  amount  1  per  cent.  The  heating  effect  on  the  incoming 
air  would  be  slight  and  I  do  not  believe  would  result  in  an  appre- 
ciable loss  in  volume  delivered.  The  results  stated  before  in- 
clude all  these  losses,  and  these  points  are  brought  up  to  show 
there  is  no  need  to  consider  these  items  as  separate  losses,  at 
least  at  the  comparatively  low  pressure  used  in  rotary  machines, 
and  as  a  matter  of  fact  it  is  probable  that,  the  case  expansion 
being  less  than  the  impeller  expansion,  the  clearance  is  reduced 
and  the  slip  decreased  to  some  extent,  probably  enough  to  offset 
the  additional  slip  due  to  the  decrease  in  the  density  of  the  gas." 

Air=compressor  Capacity. — Capacities  of  air-compressors  in 
cu.  ft.  of  free  air  per  minute  in  common  practice  are  Uoually  cal- 
culated by  multiplying  the  area  of  the  intake  cylinder  by  the  feet 
of  piston  travel  per  minute.  The  free  air  capacity  divided  by 
the  number  of  atmospheres  will  give  the  volume  of  compressed 
air  per  minute.  To  ascertain  the  number  of  atmospheres  at  any 
given  pressure,  add  14.7  Ibs.  to  the  gage  pressure,  divide  this 
sum  by  14.7,  and  the  result  will  be  the  number  of  atmospheres. 

This  calculation,  however,  is  merely  theoretical,  and  the  results 
derived  are  never  attained  in  actual  practice,  even  with  compres- 
sors of  the  very  best  design.  Allowances  should  be  made  for  vari- 
ous losses,  the  principal  one  being  due  to  clearance  spaces,  but  in 
machines  of  poor  design  and  construction  considerable  losses 
occur  through  imperfect  cooling,  leakages  past  the  piston  and 
through  the  discharge-valves,  insufficient  area  and  improper 
working  of  inlet-valves,  etc.  There  are  compressors  where  the 
total  losses  run  as  high  as  30  per  cent.,  whereas  2.5  to  10  per  cent, 
should  be  the  maximum. 

The  altitude  at  which  the  compressor  is  to  operate  is  an  impor- 
tant factor,  as  it  affects  its  capacity  in  direct  ratio  to  the  ele- 
vation. It  will  be  seen,  as  the  density  of  the  atmosphere  de- 
creases with  the  altitude,  a  compressor  at  hi?h  altitude  takes  in 
less  weight  of  air  at  each  revolution.  The  air  being  taken  in  at 
the  intake  at  a  lower  initial  pressure,  the  earlier  part  of  each 
stroke  is  occupied  in  compressing  the  air  up  to  the  normal  pres- 
sure of  14.7  Ibs.,  and  the  net  capacity  of  the  air-cylinder  is  thereby 
reduced.  The  power  required  to  drive  the  same  compressor  is 
also  less  than  at  sea-level,  but  this  decrease  being  in  lesser  ratio 
is  not  an  offset. 

Compressors  to  be  used  at  high  altitudes  should  have  the 
steam-  and  air-cylinders  properly  proportioned  to  meet  varying 
conditions.  The  first  table  on  page  103,  based  on  a  compressor 
working  at  sea-level  and  discharging  at  a  pressure  of  70  Ibs.,  in- 
dicates the  variation  of  compressors  at  different  altitudes. 


100 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE  OF  SIZES,  POWER,  AND  CAPACITIES  OF  ROOT'S  GAS- 
EXHAUSTERS. 


No.  of 
Exhauster. 

Suction  and 
Discharge 
Diameters. 

Horse-power 
at  Stated 
Speed. 

Speed  of 
Exhauster. 

Displacement 
in  Cu.  Ft.  per 
Revolution. 

Capacity  per  Hour 
in  Cu.  Ft.,  No 
Allowance  for 
Shrinkage. 

2 

4 

.75 

200 

.72 

8,600 

3 

6 

1.5 

190 

1.50 

17,100 

4 

8 

2.5 

180 

3.07 

33,150 

5 

10 

3.75 

170 

5.20 

52,140 

6 

12 

5. 

160 

8.20 

78,720 

7 

16 

7.50 

150 

12.43 

111,840 

8 

16 

11. 

140 

20. 

168,000 

8| 

20 

15.5 

130 

29. 

226,200 

9 

20 

19. 

120 

37.25 

268,200 

9i 

20 

24. 

110 

50. 

330,000 

10 

24 

29. 

100 

63.10 

378,600 

10| 

30 

36. 

95 

83. 

473,100 

11 

30 

50. 

90 

116. 

626,400 

12 

36 

80. 

85 

196. 

999,600 

14 

42 

115. 

80 

300. 

1,444,000 

NOTE. — Horse-power  figured  on  basis  of  one  pound  per  square  inch,  at 
speeds  given  in  this  table. 


WILBRAHAM-GREEN  GAS-EXHAUSTERS. 


J° 

1 
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II 

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s 

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100 

9,000 

216,000 

150 

13,950 

334,800 

4 

8 

3 

100 

18,000 

432,000 

150 

27,000 

648,000 

5 

10 

5i 

100 

33,000 

792,000 

150 

49,500 

1,188,000 

6 

12 

9 

100 

54,000 

1,296,000 

130 

70,200 

1,684,800 

7 

16 

15 

90 

81,000 

1,944,000 

125 

112,500 

2,700,000 

8A 

16 

22 

90 

118,800 

2,851,000 

125 

165,000 

3,960,000 

9A 

20 

35 

85 

178,500 

4,284,000 

115 

241,500 

5,796,000 

9s 

20 

45 

75 

202,500 

4,860,000 

110 

297,000 

7,128,000 

9i 

24 

55 

75 

247,500 

5,940,000 

110 

363,000 

8,712,000 

10 

24 

67 

70 

281,400 

6,753,600 

100 

402,000 

9,648,000 

10i 

30 

85 

70 

357,000 

8,568,000 

100 

510,000 

12,240,000 

11 

30 

112 

70 

470,400 

11,289,600 

100 

672,000 

16,128,000 

SB 

16 

25 

Special 

size 

The  above  volumes  are  the  displacement  of  the  exhausters  at  a  moderate 
speed,  without  allowing  anything  for  loss  or  shrinkage. 


EXHAUSTERS. 


101 


Is 


Q  OQ 

Is 
SB 


I-HOQO       «O«O-*CO 

l(N<Nr-l          1-H.-I1-CM 


>-*O>  OOcOrfc 
(W1*  T-HT-ICOC 
'(NO 


1CDO>        !>•  t--< 


00  O5  CO  00        ^  ^H  c 
lO^  ^CO        COCO' 


O5  WOO  >O 
<N  w£i<N 


Diame 
Fan- 
in  F 


)  i— I  »O       O5  O5-*  CO 
i^CO        COINWCN 


OiCO'OCSS       COO5^<N       OOOCOCD 


CMCOOOO        lOt-COCO        'OO5OOOJ 
Is-  CO  1C  !C        '^-fCOCO       C^WCMC^ 


OOOStNOS       O5O< 

1C-*TJH(N          THr-i< 


CO  O  ^O  ^ 
CO  CO  Is* 


>coco     r^-< 

I^HO          0>< 


>t-t>-        O  ^05 

)CO"3       iC^Tj<( 


CO  00  1C 

OOCO  1C 


So 


102  AMERICAN  GAS-ENGINEERING  PRACTICE. 


Z1 


I 


si 


85; 

^  o 


O  ^  CO  Is*       Oi*OCM>O        f>-  00  *C  GO       CO  CO  CO  'O       ^  i— i  CM  C 

'O  CO  O  CO       CM  O  00  CO       »'l  CO  <-<  O       O5  00  t-  h-       CO  CO  >O  ' 

^fCOCOCM          CMCN^H^H          i-Hi-li-li-l 


iCMOOCO  tMCMt-UJ 
>00  lO  •->  CO  >O  CMO 
)"*TfTti  COCOCOCO 


OS-HOCO      oscoco-* 

TfcOCMtM        w2In2 


O  OOOC 
OO  CO  T—  t 

TT  (NrH 


COOS  ' 
CO  *O 


S  COCO  1C  •*  OI-H  CD 
iTtiQO  •*  r-iost^-  1C 
<  COCMCM  CNi-ii-H  I-H 


os^-ico--i      coi 

'OOO  ^H  CO          i-H  I 

oor-i>co      coi 


t^  CMOS  O        O0< 
1^  "O  CM  OS        iO  { 

•^  •<*  -^  co      co  ( 


-HCO'-iCO       OOCOCO       OCO^CO       OOCOOt^-        CMCMOOb-        OCOTt<CO        IOC3SCOCO 

^COt>.CO       OOOCO"C        CO'-iOOS       COt-COCO        »C»CiC'*        MH  r}<  TJH  CO        COCOCMCM 
Tt^COCMcM        CM  ^H  t— i  i—i        T-H  T— I  ?— ( 


500       qOQOQOiC 


COOSOO  CM        CM  CO  • 

TJH.-HO5CD  COO< 

•^  ^  coco     co  coi 


CO  CO  CN  CM 


5t-00        CNCO'tfOO        CO^CDb-       COC3Sb-OS        •*  CM  CM  h.        00  •<**  ^H  Tf 
)  >C  CO        (NOOSCO       t-COCOiC        «C  »C  ^  •*        •*  T}H  CO  CO        COCMCMCM 


CO>CO5CM        CMOSt-iO        iCi-irHO        OlCMt-^H        OCOIOO5        »OT}<Tj<i-i        T^OOCO 
rtCNOO       CM^HiCCM       ^-irtir-i^H       CMCOOCO       CMOO>CCM       OOOCOCO       O  00  CO  •* 
•*  O       COCO^CO        CMOOSOO       t>-COCOiC        ^•^•^•^        -^COCOCO        COCMCMCM 


5  CM  CM  ( 


)OOiC       fcOOCDCO       OiCMt^CO 
JCOCM       ^HOiOOt-       CDCO'C'C 


"CCOtM^H       OOOt-CO       CO 


CMCOOO  t-OOCMO  OCMCOOO  iC'COOrt* 
COOOOCD  ^fCMOr-  "CcO—iO 
•^•^COCO  CO  CO  CO  CM  CMCMCMCM 


JCOOO^H        ^HiOCOCO        Tfi^nOC 
JCMOOCO        -^CMr-iO       O500IX 


oooo 

iOCO<N 


CO        CO  CM  O  'C 


f-  --IC35OCO 
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II- 

SfS 


EXHAUSTERS. 


103 


INFLUENCE  OF  ALTITUDE  ON  EFFICIENCY  OF  COMPRESSORS. 


Altitude, 
Feet. 

Barometric  Pressure. 

Volumetric  Effi- 
ciency of  Com- 
pressors, 
Per  Cent. 
Sea-level  =  100. 

Loss  of 
Capacity, 
Per  Cent. 

Decreased 
Power 
Required, 
Per  Cent. 

Inches 
Mercury. 

Pounds  per 
Square  Inch. 

1,000 

28.88 

14.20 

97 

3 

1.8 

2,000 

27.80 

13.67 

93 

7 

3.5 

3,000 

26.76 

J3.16 

90 

10 

5.2 

4,000 

25.76 

12.67 

87 

13 

6.9 

5,000 

24.79 

12.20 

84 

16 

8.5 

6,000 

23.86 

11.73 

81 

19 

10.1 

7,000 

22.97 

11.30 

78 

22 

11.6 

8,000 

22.11 

10.87 

76 

24 

13.1 

9,000 

21.29 

10.46 

73 

27 

44.6 

10,000 

20.49 

10.07 

70 

30 

16.1 

11,000 

19.72 

9.70 

68 

32 

17.6 

12,000 

18.98 

9.34 

65 

35 

19.1 

13,000 

18.27 

8.98 

83 

37 

20.6 

14,000 

17.59 

8.65 

60 

40 

22.1 

15,000 

16.93 

8.32 

58 

42 

23.5 

The  National  Tube  Co.  has  compiled  the  following  table: 

HORSE-POWER  REQUIRED  TO  COMPRESS  100  CUBIC  FEET  FREE  AIR  FROM 
ATMOSPHERIC  TO  VARIOUS  PRESSURES. 


Gage 
Pressure, 
Pounds 
per  Sq.  In. 

One-stage 
Compression, 
D.H.P. 

Gage 
Pressure, 
Pounds 
per  Sq.  In. 

Two-stage 
Compression, 
D.H.P. 

Four-stage 
Compression, 
D.H.P. 

10    . 

3.60 

60 

11.70 

10.80 

15 

5.03 

80 

13.70 

12.50 

20 

6.28 

100 

15.40 

14.20 

25 

7.42 

200 

21.20 

18.75 

30 

8.47 

300 

24.50 

21.80 

35 

9.42 

400 

27.70 

24.00 

40 

10.30 

500 

29.75 

25.90 

45 

11.14 

600 

31.70 

27.50 

50 

11.90 

700 

33.50 

28.90 

55 

12.67 

800 

34.90 

30.00 

60 

13.41 

900 

36.30 

31.00 

70 

14.72 

1000 

37.80 

31.80 

80 

15.94 

1200 

39.70 

33.30 

90 

17.06 

1600 

43.00 

35.65 

100 

18.15 

2000 

45.50 

37.80 

2500 

39.06 

3000 

40.15 

D.H.P.  =  delivered  horse-power  at  compressor  cylinder. 


104 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


Another  table  is  as  follows: 

HORSE-POWER  DEVELOPED  IN  COMPRESSING  ONE  CUBIC  FOOT  OF  FREE 
AIR  FROM  ATMOSPHERIC  PRESSURE  (14.7  POUNDS)  TO  VARIOUS  GAGE 
PRESSURES. 

Initial  Temperature  of  the  Air  in  Each  Cylinder  Taken  as  60°  F. 
(Jacket  Cooling  Not  Considered.) 


Gage 
Pressure. 

Isothermal 
Compression. 

Adiabatic  Compression. 

One  Stage. 

Two  Stage. 

Three  Stage. 

Four  Stage. 

10 

0.0332 

0.0358 

20 

0.0551 

0.0623 

30 

0.0713 

0.0842 

40 

0.0842 

0.1026 

50 

0.0950 

0.1187 

60 

0.1042 

0.1331 

70 

0.1122 

0.1465 

0.128 

0.122 

0.119 

80 

0.1194 

0.1585 

0.137 

0.131 

0.127 

90 

0.1258 

0.1695 

0.146 

0.139 

0.135 

100 

0.1317 

0.1800 

0.154 

0.146 

0.142 

125 

0.1443 

0.2036 

0.171 

0.161 

0.157 

150 

0.1549 

0.2244 

0.186 

0.174 

0.169 

200 

0.1719 

0.2600 

0.210 

0.196 

0.190 

300 

0.1964 

0.3164 

0.247 

0.229 

0.220 

400 

0.2141 

0.3613 

0.276 

0.253 

0.242 

500 

0.2279 

0.3889 

0.299 

0.272 

0.260 

600 

0.2393 

0.4318 

0.318 

0.288 

0.275 

700 

0.2489 

0.4608 

0.335 

0.302 

0.289 

800 

0.2573 

0.4873 

0.349 

0.314 

0.299 

900 

0.2649 

0.5114 

0.363 

0.325 

0.310 

1000 

0.2720 

0.5337 

0.375 

0.335 

0.318 

1200 

0.2820 

0.5742 

0.397 

0.353 

0.333 

1400 

0.2924 

0.6102 

0.414 

0.368 

0.347 

1600 

0.3012 

0.6427 

0.432 

0.381 

T).359 

1800 

0.3087 

0.6724 

0.447 

0.393 

0.369 

2000 

0.3154 

0.7003 

0.460 

0.403 

0.379 

NOTE. — The  above  values  are  for  sea-level  conditions  only. 

The  loss  in  delivery  of  power  in  compressed  air  and  gas 
(approximately)  for  single-stage  compression  will  average  perhaps 
30  per  cent.,  while  that  of  two-stage  compression  will  perhaps 
not  exceed  17  per  cent.,  while  four-stage  compression  reduces  the 
transmission  loss  to  about  8  per  cent.;  as  a  stand-off  against  this 
economy,  of  course,  is  the  additional  initial  power  necessary  to 
overcome  the  resistance  and  friction  caused  by  additional  valves, 
ports,  coolers,  etc.,  which  may  require  an  increase  of  from  10  to 
15  per  cent. 

There  is  also  a  reduction  of  the  unit  strain  upon  the  apparatus, 
all  depending  largely,  however,  for  its  efficiency  upon  the  details 


EXHAUSTERS. 


105 


PRESSURE  AND  VOLUME  OF  COMPRESSED  AIR     (SHONE). 


Pressure  above 
Atmosphere. 

Comparative 
Volume  of  Air 
after  Compression. 
Initial  Volume  =  1. 

Tempera- 
ture by 
Adiabatic 
Compres- 
sion, that 

Rate  of 
Com- 
pression 

Average  Load 
against  Compress- 
ing Piston,  per 
Square  Inch. 

of  the 

Isother- 

Free  Air 

mally. 

Isother- 

Adia- 

being  60° 

Isother- 

Adia- 

mally. 

batically 

F. 

mally. 

batically. 

Lbs.  per 
Sq.  In. 

Inches  of 
Mercury. 

Feet  of 
Water. 

Volume. 

Volume. 

Fahr. 

Com- 
pression. 

Load. 

Load. 

2.041 

2.31 

0.936 

0.954 

70.04 

.0680 

0.967 

0.976 

2 

4.082 

4.61 

0.880 

0.913 

79.64 

.1361 

1.876 

1.910 

3 

6.123 

6.92 

0.831 

0.876 

88.84 

.2041 

2.730 

2.805 

4 

8.164 

9.23 

0.786 

0.843 

97.68 

.2721 

3.538 

3.664 

5 

10.205 

11.54 

0.746 

0.812 

106.18 

.3401 

5.303 

4.491 

6 

12.246 

13.84 

0.710 

0.784 

114.39 

.4081 

5.031 

5.288 

7 

14.287 

16.15 

0.677 

0.758 

122.32 

.4762 

5.725 

6.060 

g 

16.328 

18.46 

0.648 

0.735 

129.99 

.5442 

6.387 

6.806 

9 

18.369 

20.76 

0.620 

0.713 

137.43 

.6122 

7.021 

7.529 

10 

20.410 

23.07 

0.595 

0.692 

144.65 

.6803 

7.629 

8.232 

11 

22.451 

25.38 

0.572 

0.673 

151.66 

.7483 

8.212 

8.914 

12 

24.492 

27.68 

0.551 

0.655 

158.48 

.8164 

8.774 

9.578 

13 

26.533 

29.99 

0.531 

0.638 

165.13 

.8844 

9.315 

10.224 

14 

28.574 

32.30 

0.512 

0.622 

171.60 

.9524 

9.836 

10.854 

15 

30.615 

34.61 

0.495 

0.607 

177.92 

2.0204 

10.338 

11.468 

16 

32.656 

36.91 

0.479 

0.593 

184.09 

2.0884 

10.825 

12.068 

17 

34.697 

39.22 

0.464 

0.579 

190.11 

2.1565 

11.297 

12.654 

18 

36.738 

41.53 

0.450 

0.567 

196.01 

2.2245 

11.753 

13.227 

19 

38.779 

43.83 

0.436 

0.555 

201.77 

2.2925 

12.193 

13.788 

20 

40.820 

46.14 

0.424 

0.544 

207.42 

2.3605 

12.623 

14.337 

21 

42.861 

48.45 

0.412 

0.533 

212.95 

2.4286 

13.044 

14.875 

22 

44  .  902 

50.75 

0.401 

0.522 

218.37 

2.4966 

13.450 

15.403 

23 

46  .  943 

53.06 

0.390 

0.512 

223  .  69 

2  .  5646 

13.844 

15.921 

24 

48.984 

55.37 

0.380 

0.503 

228.91 

2.6327 

14.230 

16.429 

25 

51.025 

57.68 

0.370 

0.494 

234.03 

2.7007 

14.604 

16.927 

26 

53.066 

59.98 

0.361 

0.485 

239.07 

2.7687 

14.970 

17.419 

27 

55.107 

62.29 

0.353 

0.477 

244.02 

2.8367 

15.327 

17.898 

28 

57.148 

64.60 

0.344 

0.469 

248.88 

2.9048 

15.676 

18.371 

29 

59.189 

66.90 

0.336 

0.461 

253.66 

2.9728 

16.016 

18.837 

30 

61  .  230 

69.21 

0.329 

0.454 

258.37 

3.0408 

16.348 

19.294 

31 

63.271 

71.52 

0.322 

0.447 

263.00 

3.1088 

16.673 

19.745 

32 

65.312 

73.82 

0.315 

0.440 

267  .  56 

3.1769 

16.992 

20.190 

33 

67.353 

76.13 

0.308 

0.434 

272.05 

3  .  2449 

17.303 

20.626 

34 

69.394 

78.44 

0.302 

0.427 

276.48 

3.3129 

17.608 

21.056 

35 

71.435 

80.75 

0.296 

0.421 

280.84 

3.3810 

17.907 

21.480 

36 

73.476 

83.05 

0.290 

0.415 

285.14 

3  .  4490 

18.200 

21.899 

37 

75.517 

85.36 

0.284 

0.409 

289.38 

3.5170 

18.487 

22.312 

38 

77.558 

87.67 

0.279 

0.404 

293.56 

3  .  5850 

18.768 

22.718 

39 

79.599 

89.97 

0.274 

0.399 

297.68 

3.6531 

19.045 

23.121 

40 

81  .  640 

92.28 

0.269 

0.393 

301.75 

3.7211 

19.316 

23.516 

41 

83.681 

94.59 

0.264 

0.388 

305.77 

3.7891 

19.581 

23.908 

42 

85.722 

96.89 

0.259 

0.383 

309.74 

3.8571 

19.844 

24.293 

43 

87.763 

99.20 

0.255 

0.379 

313.66 

3.9252 

20.101 

24.675 

44 

89.804 

101.51 

0.250 

0.374 

317.53 

3.9932 

20.353 

25.052 

45 

91.845 

103.82 

0.246 

0.370 

321.36 

4.0612 

20.602 

25.424 

46 

93.686 

106.12 

0.242 

0.365 

325.13 

4.1293 

20.846 

25.729 

47 

95.927 

108.43 

0.238 

0.361 

328.87 

4.1973 

21.086 

26.155 

48 

97.968 

110.74 

0.234 

0.357 

332.56 

4  .  2653 

21.323 

26.515 

49 

100.009 

113.04 

0.231 

0.353 

336.21 

4.3333 

21.555 

26.870 

50 

102.050 

115.35 

0.227 

0.349 

339.82 

4.4014 

21.784 

27.221 

106 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


of  design.  For  low  pressures  the  saving  acquired  is  hardly  justified 
by  the  multiplication  of  cylinders  and  the  losses  attendant  upon 
the  operation  of  numerous  additional  parts.  Best  practice  recom- 
mends the  use  of  the  single-sta:,e  compressor  up  to  70  or  100  Ibs., 
above  that  amount  (preferably  75  Ibs.)  the  use  of  the  compound 
(two-,  three-,  or  four-stage  type  compressor). 

Of  course,  as  beforesaid,  these  matters  are  largely  a  matter  of 
design,  the  theory  being  that  the  ratios  of  the  cylinders  should 
be  such  that  the  final  temperatures  'and  M.E.P.  in  each  cylinder 
should  be  identical,  thereby  effecting  an  equal  distribution  of  the 
work  throughout. 

LOSS  OF  WORK  DUE  TO  HEAT  IN  COMPRESSING  AIR  FROM  ATMOSPHERIC 
PRESSURE  TO  VARIOUS  GAGE  PRESSURES  BY  SIMPLE  AND  COMPOUND 
COMPRESSION. 

(Air  in  Each  Cylinder:  Initial  Temperature,  60°  F.) 


One  Stage. 

Two  Stage. 

Three  Stage. 

Four  Stage. 

Percentage  of  Work  Lost  in  Terms  of 

I 

j 

j 

•  j 

1 

j 

1 

d 

j 

i 

13  « 

o  1 

"3  1 

.s  i 

-     *-» 

.si 

"*  1 

o  | 

E 

§  ft 

**"*  CL 

S    £^ 

"***  ft 

£  ft 

+s  Q^ 

§  a 

"S  ft 

5 

o 

11 

A  3 

1° 

ji 

I1 

ji 

II 

T 

J1 

V 

jl 

60 

29.9 

23.0 

13.4 

11.8 

8.6 

7.9 

4.7 

4.5 

70 

30.6 

23.4 

14.1 

12.4 

8.7 

8.0 

6.1 

5.7 

80 

32.7 

24.6 

14.7 

12.8 

9.7 

8.9 

6.4 

6.0 

90 

34.7 

25.8 

16.1 

13.8 

10.5 

9.5 

7.3 

6.8 

100 

36.7 

26.8 

16.9 

14.5 

10.9 

9.8 

7.8 

7.3 

125 

41.1 

29.2 

18.5 

15.6 

11.6 

10.4 

8.8 

8.1 

150 

44.8 

30.9 

20.1 

16.7 

12.3 

10.9 

9.1 

8.4 

200 

51.2 

33.9 

22.2 

18.1 

14.0 

12.3 

10.5 

9.5 

300 

61.2 

37.9 

25.7 

20.5 

16.6 

14.2 

12.0 

10.7 

400 

68.7 

40.7 

28.9 

22.4 

18.2 

15.4 

13.1 

11.5 

500 

70.6 

41.4 

31.2 

23.8 

19.3 

16.2 

14.1 

12.3 

600 

80.4 

44.5 

32.8 

24.7 

20.4 

16.9 

14.9 

13.0 

700 

85.0 

46.0 

34.6 

25.7 

21.3 

17.6 

16.1 

13.8 

800 

89.5 

47.2 

35.7 

26.3 

22.0 

18.1 

16.2 

13.9 

900 

93.0 

48.2 

37.1 

27.0 

22.6 

18.5 

16.6 

14.4 

1000 

96.1 

49.0 

37.9 

27.5 

23.2 

18.8 

16.9 

14.5 

1200 

102.8 

50.7 

40.3 

28.8 

24.8 

19.9 

17.7 

15.0 

1400 

108.6 

52.0 

41.5 

29.3 

25.9 

20.5 

18.6 

15.7 

1600 

113.4 

53.1 

43.5 

30.3 

26  .  5 

20.9 

19.2 

16.1 

1800 

117.5 

54.0 

44.8 

31.0 

27.3 

21.2 

19.6 

16.4 

2000 

122.0 

55.0 

45.8 

31.4 

27.5 

21.5 

19.9 

16.5 

EXHAUSTERS.  107 

The  following  are  a  few  of  the  formulas  used  by  the  B.  F. 
Sturtevant  Manufacturing  Company,  large  makers  of  blowers, 
exhausters,  fans,  etc. .  for  calculating  horse-power  requisite  for  the 
compression  of  various  quantities  of  air  under  various  conditions: 

V         HP  "$).       "          - 

W  .  33,000     ' 


(2) 


ll,UU) 


33,000 
Ibs.  per  sq.  in.xF 

HJ-= 

where  V=  volume  of  free  air  in  cubic  feet  per  minute; 

P=  pressure  of  the  atmosphere  or  suction  pressure  (absolute) 

in  Ibs.  per  sq.  ft.  ; 
P1  =  pressure  of  compression  (absolute)  in  Ibs.  per  sq.  ft. 

Of  the  above,  formula  (1)  is  principally  used  when  the  H.P. 
required  is  for  air  which  is  cooled  during  compression,  as  in  ordinary 
compressor  practice. 

Formula  (2)  when  the  air  is  assumed  to  be  compressed  so 
quickly  that  it  does  not  return  to  atmospheric  temperature.  This 
is  the  usual  case  in  all  blower  work. 

Formula  (3)  is  generally  known  as  the  "  hydraulic"  formula, 
and  in  common  practice  is  rarely  used  above  five  ounces  to  half  a 
pound. 

Formula  (4)  is  usually  adopted  in  the  case  of  positive  com- 
pressors, etc.,  no  allowance  being  made  in  this  formula  for  "slip," 
the  calculation  being  "net." 


108 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


DIRECT-CONNECTED  EXHAUSTERS,  Nos.  1  TO  8  (Inclusive). 

ISBELL-PORTER  CO.,  NEWARK,  N.  J. 
(For  data  see  page  111.) 


PLAN  OF  BED-PLATE 


EXHAUSTERS. 


109 


GEARED  COMBINATION  EXHAUSTERS,  Nos.  7  TO  12  (Inclusive). 

ISBELL-PORTER  CO.,  NEW  YORK  AND  NEWARK,  N.  J. 
(For  data  see  page  111.) 


PLAN  OF  BED-PLATE 


110 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


COMBINATION  EXHAUSTERS,  Nos.  13  TO  15  (Inclusive). 

ISBELL-PORTER  CO,  NEWARK,  N.  J. 
(For  data  see  page  111.) 


PLAN  OF  BED-PLATE 


EXHAUSTERS. 


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CHAPTER  IX. 
STATION=METERS. 

Sizes. — Perhaps  one  of  the  most  radical  improvements  in 
connection  with  machinery  about  the  works  which  has  presented 
itself  within  many  years  is  the  introduction  of  the  Hinman  drum 
in  station-meters.  The  advantage  of  this  drum  is  that  it  increases 
largely  the  capacity  of  the  meter  without  increasing  its  cost 
or  bulk. 

CAPACITY   OF   STATION-METERS    (OLD   TYPE). 
Feet.  Cu.  Ft.  per  Hr. 

3X3  1,250 

3.5X  3.5  2,175 

4X4  3,400 

4.5X  4.5  5,000 

5X5  6,800 

5.5X  5.5  8,650 

6X6  10,800 

6.5X  6.5  13,000 

7X7  16,700 

7.5X  7.5  19,300 

8X8  21,857 

8.5X  8.5  25,000 

9X9  28,650 

9.5X  9.5  32,300 

10  X10  36,450 
10.5X10.5  41,700 

11  Xll  46,875 
11.5X11.5  52,000 

12  X12  62,500 

The  following  are  the  capacities  of  station-meters  of  the  Hin- 
man drum  type,  as  manufactured  by  the  American  Meter  Com- 
pany : 

112 


STA1  ION-METERS.  113 

CAPACITY  OF  STATION-METERS    (HINMAN   DRUM  TYPE). 

Feet.  Cu.  Ft.  per  Hr. 

6  X6  22,000 
6.5X6.5  25,750 

7  X7  30,000 
7.5X7.5  35,000 

8  X8  40,000 

9  X9  52,000 

Connections. — A  station-meter  should  be  thoroughly  cleaned 
at  least  twice  a  year,  and  should  be  tested  for  accuracy  as  often 
as  cleaned.  Fig.  22  shows  the  proper  connections  for  proving  a 


FIG.  22. — Connections  for  Proving  Station-meter. 

station-meter.  The  test-meter  should  be,  say,  a  60-light  meter 
recently  proved  on  the  regular  shop  meter-prover,  and  should 
be  connected  in  as  a  shunt  by-passing  the  inlet-valve  on  the  sta- 
tion-meter. At  least  400  feet  of  gas  should  be  passed,  and  the 
adjustment  made  by  changing  the  station-meter  water-line. 
The  bearings  of  the  meter  should  at  all  times  be  carefully  oiled, 
especially  in  case  of  the  Hinman  type,  which  revolves  much  faster 
than  the  old-style  meter. 

While  the  proving  meter  is  attached,  the  outlet-valve  of  the 
meter  should  be  closed.  Should  the  index  of  the  proving  meter 
move,  a  leakage  will  be  indicated  in  the  shell  and  connection  of 
the  meter.  Should  the  index  of  the  prover  move  and  that  of 
the  station-meter  remain  stationary,  it  would  indicate  a  leak- 
age through  the  drum  of  the  meter.  Great  care  must  be  taken, 
however,  as  to  the  tightness  of  the  valves  or  leaks  in  the  con- 
nections. 

The  accompanying  sketch  (Fig.  23)  shows  the  by-pass  con- 
nection of  the  station-meter,  which  should  be  invariably  used 


114 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


in  connecting  in  the  meter  with  the  mains.  By  opening  the 
valve  on  the  main  run  of  pipe  and  closing  the  valve  on  the  risers, 
the  meter'  is  by-passed,  while  by  closing  the  valve  on  the  main 
run  and  opening  the  valves  on  the  risers,  the  meter  is  thrown 
into  service. 

It  will  be  found  of  advantage  to  use  valves  for  this  service  of 
the  quick-opening  type,  especially  when  the  sizes  of  the  connec- 
tions are  under  13  in.  Such  valves  are  manufactured  by  the 
P.  H.  &  F.  M.  Roots  Mfg.  Co.  The  advantage  to  be  obtained 
by  these  valves  is  the  extreme  rapidity  with  which  they  can  be 
worked  in  throwing  in  and  out  the  by-pass,  and  the  saving 
of  labor  entailed  by  the  old  screw-type  of  valve.  Not  only  the 


Fi3.  23. — Rear  End  and  Side  View  of  Station-meter. 

meter  but  the  exhauster  should  also  be  by-passed  after  the  man- 
ner elsewhere  described,  and  there  should  be  a  by-pass  between 
the  inlet  and  the  outlet  of  the  storage-holder,  in  addition  to  which 
the  works  connection  should  be  so  flexible  as  to  form  almost  any 
by-pass  combination.  For  example,  there  should  be  a  connection 
from  the  works  direct  to  the  storage-holder,  also  direct  to  the 
town  from  the  outlet  of  the  purify  ing -boxes,  and  from  the  works 
through  the  purifying-boxes  to  the  town  without  the  intermedia- 
tion of  any  holder.  It  should  also  be  possible  to  reverse  the  direc- 
tion of  flow  through  almost  any  section  of  the  works  yard-con- 
nections. 


STATION-METERS.  115 

Volume  Correction.  —  A  thermometer  should  be  so  attached 
to  every  station-meter  as  to  indicate  the  temperature  of  gas  on 
the  inlet,  the  volume  of  which  should  be  corrected  to  a  standard 
temperature  of  60°  F.  and  a  pressure  of  30  in.  of  mercury,  a  table 
being  used  for  this  purpose  which  is  based  upon  the  following 
formula: 

l7M(h-a)v 
(460  +  Q     ' 

where  F=the  corrected  volume  at  60°  and  30  in.; 

•y  =  the  volume  observed  at  a  temperature  of  t°  and  h  in.; 
h  =  barometer  pressure,  inches  of  mercury  observed; 
a  =  the  tabular  tension  of  aqueous  vapor  at  t°. 
This  formula  may   be    expressed  as  follows:   The    corrected 
volume   of   a  gas   saturated   with   water-vapor   at   the   standard 
conditions  of  60°  F.  and  30  in.  barometric  pressure  is  equal  to 
the   observed   volume  multiplied   by    17.64   tunes   the  difference 
between   the  observed   barometric   pressure  and  the  tension   of 
water-vapor  at   the    observed   temperature  and  divided  by  the 
sum  of  460  plus  the  observed  temperature  in  Fahr.  degrees.     The 
tension  of  water-vapor    for  the  observed  temperature  must  be 
found  from  the  table  giving  the  tensions  for  the  different  tem- 
peratures. 

The  formula  is  derived  in  the  following  manner: 
Representing  the  volume  at  60°  F.  and  30  in.  pressure  by  V, 
and  that  of  the  same  mass  of  gas  at  any  other  temperature  t  and 
any  other  pressure  h  by  v,  we  can  form  the  laws  governing  the 
change  of  volume  of  gases  under  the  influence  of  changes  in  tem- 
perature and  pressure,  and  derive  the  required  formula  for  dry  gases. 
Since  the  volume  varies  inversely  as  the  pressure,  the  product 
obtained  by  multiplying  the  volume  at  any  pressure  by  that 
pressure  is  equal  to  the  product  obtained  by  multiplying  the 
volume  of  the  same  mass  of  gas  at  any  other  pressure  by  the 
corresponding  pressure,  and  we  have 

307=^,    or    F- 


Gases  expand  or  contract  ^j-j-  part  of  their  volume  at  32°  F. 
for  each  change  in  temperature  of  1°  F.,  hence  the  effect  of  tem- 
perature is  shown  by  the  equation  460  +  ^  =  520  for  60°,  since  t 
is  the  number  of  degrees  above  0  ;  therefore  460  +  1  is  equal  to  492 
at  freezing-point  or  32°  F.,  while  520  is  the  number  of  parts  to 


116  AMERICAN   GAS-ENGINEERING  PRACTICE. 

which  492  parts  at  32°  will  have  expanded  when  the  tempera- 
ture is  raised  to  60°.     From  this  we  obtain 


v_ 

460+*' 

Combining  these  two  equations,  we  have  for  dry  gases 

520vh 


V= 


30(460  +  0' 


that  is,  the  volume  corrected  to  the  standard  conditions  of  60°  F. 
and  a  pressure  of  30  in.  of  mercury  is  equal  to  the  observed  volume 
multiplied  by  the  observed  pressure  in  inches  of  mercury  mul- 
tiplied by  520  and  divided  by  30  times  the  sum  of  460  plus  the 
observed  temperature. 

The  correction  for  moisture  depends  on  the  fact  that  a  gas 
saturated  with  water-vapor,  as  will  be  a  gas  in  contact  with  water, 
will,  under  the  same  conditions  of  temperature  and  pressure, 
always  contain  the  same  quantity  of  water-vapor.  This  vapor 
exerts  a  certain  pressure,  which  increases  with  the  temperature 
and  is  proportional  to  the  amount  of  vapor  present.  The  pres- 
sure so  exerted  has  been  determined  in  inches  of  mercury  for 
each  degree  of  temperature.  To  correct  for  the  presence  of  mois- 
ture in  a  gas  saturated  with  water-vapor  it  is  necessary  to  deduct 
the  pressure  due  to  the  tension  of  this  vapor  from  the  observed 
barometric  pressure,  since  this  barometric  pressure  is  resisted 
partly  by  the  pressure  of  the  water-vapor  and  partly  by  that 
of  the  gas,  and  therefore  the  pressure  exerted  on  the  gas  will  be 
really  only  the  difference  between  the  barometric  pressure  and 
the  pressure  due  to  the  tension  of  the  water- vapor.  Calling  this 
tension  of  water-vapor  a  and  taking  its  value  at  the  temperature 
of  60°  (0.518)  to  deduct  from  the  standard  barometric  pressure 
of  30  in.,  we  have  for  the  formula  for  reducing  the  volume  of  gas 
saturated  with  water-vapor  observed  at  any  temperature  and 
pressure  to  that  of  gas  saturated  with  water-vapor  at  60°  and  30  in., 

(h-a)52()v  (h-a)52Qv 


(30 -0.518)  (460+0      29.482(460+0' 

or  dividing  both  numerator  and  denominator  of  the  fraction  by 
29.482,  we  get 

v     17M(h-a)v 

460 +*      ' 


STATION-METERS.  117 

Standard  Unit  of  Volume. — Some  investigation  on  the  part 
of  the  writer  has  revealed  the  astonishing  fact  that  there  is  no 
universally  established  standard  in  the  United  States  to  which 
station-meter  registrations  are  corrected;  that  any  number  of 
standards  of  an  arbitrary  nature  exist,  the  most  common  being 
the  average  pressure  and  temperature  at  which  gas  is  distributed 
to  the  consumer's  meter,  this  being  for  the  sake  of  checking  up 
with  the  sum  total  of  the  said  meters,  the  difference  being  bal- 
anced by  the  item  of  "gas  unaccounted  for,"  covering  shrinkage, 
leakage,  and  non-registering  of  meters. 

As,  however,  the  standard  pressure  throughout  the  country 
varies  very  widely,  this  will  not  prove  a  satisfactory  basis  for 
the  comparison  of  manufacturing  results,  and  the  writer  there- 
fore suggests  that  there  should  be  two  corrections  for  meter  meas- 
urements, the  one  for  the  benefit  of  distribution  results  as  above 
noted,  the  other  the  universal  standard  for  gas  comparison  meas- 
urements of  60  deg.  F.  and  29.7  or,  usually,  30  in.  barometric 
pressure. 

It  is  scarcely  necessary  to  lay  further  emphasis  upon  the  ad- 
vantage of  having  these  two  standards  of  comparison  univer- 
sally adopted,  for  only  by  some  such  means  can  any  uniformity 
of  results  or  exactness  of  data  be  obtained.  The  latter  or  atmos- 
pheric standard  is  now  universally  in  vogue  in  light  measure- 
ments and  standard  photometry. 

The  writer  further  suggests  that  the  temperature  in  both 
equations  for  measurement  should  be  taken  from  the  gas  itself, 
and  not  the  station  atmosphere,  as,  in  small  or  large  works  where 
the  storage  capacity  is  limited,  the  gas  is  frequently  forced 
through  the  meter  not  only  under  extraordinary  pressure  but  at 
a  high  degree  of  temperature. 

It  will  now  be  seen  that  under  such  conditions  there  can  be  no 
uniform  comparison  of  measurements,  as  they  will  vary  at  different 
seasons  of  the  year,  by  reason  of  both  temperature  and  demand 
upon  manufacture,  due,  for  example,  to  such  details  as  the  ratio 
between  condensing  capacity  and  amount  of  gas  manufactured, 
this  being  inverse,  as  well  as  the  actual  atmospheric  tempera- 
ture. 

In  order  to  avoid  any  possible  difference  in  the  conditions,  or 
bases  of  comparison  of  manufacturing  results,  measurement,  or 
data,  the  writer  strongly  urges  that  all  such  figures  be  generally 
understood,  without  further  particularization,  as  being  based 
upon  the  universal  standard  of  30  in.  barometric  pressure  and 
60  deg.  F. 

Roughly  speaking,  all  gases  expand  nearly  1  per  cent,  for  every 
5  degrees  rise  in  temperature.  The  volume  of  the  gas  varies  di- 


118  AMERICAN  GAS-ENGINEERING  PRACTICE. 

rectly  as  the  absolute  temperature,  and  inversely  as  the  absolute 
pressure. 

One  of  the  most  convenient  ways  for  correcting  the  station- 
meter  measurement  of  gas  for  pressure,  where  the  pressure  is 
exerted  by  the  weight  of  the  holder  (which  is  approximately  con- 
stant), is  to  set  the  station-meter  a  sufficient  amount  fast  to  com- 
pensate for  this  difference.  This  method,  however,  has  its  draw- 
backs; one,  for  example,  being  where  it  is  necessary  to  reduce 
the  reading  to  average  pressure  and  temperature  of  distribution 
for  the  purpose  of  balancing  up  and  checking  consumers'  meters, 
gas  unaccounted  for,  etc.  It  is  perhaps  better  to  convert  the 
holder  pressure,  usually  in  inches  of  water,  to  inches  of  mercury, 
by  the  use  of  coefficient  0.0735  inch  and  correcting  by  use  of 
the  table  elsewhere  given. 

Operation  Hints. — There  should  be  a  pressure-gage  on  the 
inlet  and  one  on  the  outlet  of  the  station-meter,  the  difference 
in  their  registration  forming  the  differential  pressure.  This  should 
in  no  instance  exceed  1.5  in.,  a  greater  resistance  indicating  that 
the  meter  is  forced.  The  valves  on  the  pressure-gages,  as  well 
as  on  the  water-line,  should  be  opened  and  closed  occasionally,  and 
if  much  dirt  collects  on  the  glass  of  the  gages,  the  valves  should 
remain  open  only  just  wide  enough  to  admit  the  pressure,  thus 
excluding  a  certain  amount  of  dirt  and  lessening  the  rapidity 
of  circulation.  It  will  also  prevent  excessive  fluctuation  of  the 
meniscus  in  the  gage-glass.  The  stream  of  water  which  is  fed 
to  the  meter  should  be  just  sufficient  to  keep  a  correct  water- 
level,  the  discharge-pipe  on  the  overflow  just  dripping.  The  over- 
flow-gage on  the  rear  head  of  the  meter  is  intended  to  show 
that  the  water  in  the  drum  is  at  its  proper  level.  Care  should  be 
taken  that  its  opening  and  connections  should  at  all  times  be 
free  of  obstruction,  as  upon  this  depends  the  accuracy  of  the 
meter.  The  top  of  the  overflow-gage  should  be  connected  to 
the  inlet-pipe  of  the  meter  only,  and  the  bottom  should  be  trapped 
close  to  the  gage.  This  trap  should  be  allowed  to  discharge 
through  a  funnel  and  should  not  in  any  way  be  connected  to 
any  waste-pipe  or  sewer,  as  such  an  arrangement  is  liable  to 
siphon  the  water  from  the  meter. 

The  index  of  the  meter  should  be  kept  clean  and  occasionally 
oiled  with  some  high-grade  clock-oil.  The  train  of  gears  may 
be  occasionally  greased  with  a  little  tallow  or  graphite,  as  should 
the  spindle  running  through  the  front  head  of  the  meter,  around 
which  the  packing  should  be  changed  whenever  it  becomes  hard. 
This  packing  may  consist  of  leather  washers,  yarn,  tallow,  or 
graphite. 

At  times  a  grinding  or  pounding  noise  may  be  heard  inside 


STATION-METERS.  119 

the  meter,  especially  during  maximum  load.  This  may  occur 
from  a  break  or  buckle  in  the  plates  of  the  drum,  the  drum-centers 
being  loose  on  the  shaft,  or  from  lost  motion  on  the  part  of  the 
shaft  in  si  worn  journal,  or  from  the  grinding  of  the  drum  due 
to  thrustjon  the  part  of  the  shaft. 

As  before  stated,  when  the  station-meter  is  tested  the  water- 
line  should  be  carefully  established,  and  a  bench-mark  placed 
upon  the  meter-case.  This  being  done,  a  daily  inspection  should 
approve  the  conformity  of  the  meniscus  in  the  water-gage  to 
such  mark.  This  mark  should  be  invariably  located  after  the 
final  establishment  of  the  meter,  instead  of  relying  upon  the 
shop-mark  usually  placed  by  the  manufacturer. 

One  method  of  correcting  meter  measurement  for  holder  pres- 
sure is  to  connect  a  U  gage  on  the  inlet  of  the  meter  and 
fill  it  with  mercury.  The  reading  of  this  gage  may  be  added  to 
that  of  the  barometer  and  the  sum  of  their  readings  compared 
with  a  table  for  correction. 

ROTARY  METERS. 

The  Rotary  Meter  Co.  of  New  York  City  have  recently  placed 
upon  the  market  a  form  of  station-meter  which,  although  in- 
vented by  Mr.  Thomas  Thorp,  the  pioneer  of  the  "slot  meter," 
some  years  since,  and  well  known  for  some  time  in  English  works, 
is  new  to  the  American  market. 

The  principle  of  the  meter,  which  is  illustrated  by  Fig.  24,  is 
that  of  the  anemometer,  and  it  is  adapted  at  high  or  low  pressure 
to  air,  natural  or  any  and  all  forms  of  manufactured  gas. 

The  safe  working  pressure  of  these  meters  is  up  to  150  Ibs., 
and  they  are  arranged  in  the  case  of  high  pressure  to  compensate, 
the  reading  being  mechanically  corrected  to  indicate  the  flow  of 
gas  at  atmospheric  pressure. 

The  minimum  measuring  capacity  of  these  meters  is  one-tenth 
that  of  the  maximum  capacity,  the  meter  registering  accurately 
only  between  these  limits. 

The  chief  claims  for  this  type  of  meter  are  its  small  size  (one- 
tenth  the  bulk  of  the  old  type  station-meter),  low  cost  (one-half 
that  of  the  old  type),  and  extreme  durability.  The  cheapness  and 
small  size  of  these  meters  bring  them  within  the  range  of  works 
economy,  to  meter  the  output  of  various  sections  of  apparatus,  and 
thus  to  analyze  the  conditions  of  output  in  a  manner  impossible 
under  the  old  arrangement. 

In  this  connection  the  same  company  are  getting  out  a  small 
consumer's  meter  (see  Fig.  25),  which  is  known  in  England  as  a 
"  rebate  meter"  by  reason  of  its  use  for  determining  the  amount 


120 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


of  gas  usei  by  the  consumer  for  other  than  illuminating  purposes, 
upon  which  special  concessions  were  made.     It  is  likely  that  the 


FIG.  24. — Section  of  Rotary  btation-meter. 

use  of  such  meters,  connected  directly  upon  the  gas-burning  appli- 
ance and  continually  beneath  the  eye  of  the  consumer,  will  in 
the  future  materially  increase  economy  in  operation. 


ROTARY  STATION-METERS. 


Cu.  Ft. 

Cu.  Ft. 

Dimensions  in  Inches. 

No. 

per  Hr., 

per  Hr., 

Weight, 

Minimum 
Capacity. 

Maximum 
Capacity. 

A 

B 

C 

D 

E 

F 

Pounds. 

1 

150 

1,500 

13* 

9 

4f 

7i 

3 

54 

62 

2 

350 

3,500 

16 

13 

9| 

9| 

4 

10 

166 

3 

500 

5,000 

24 

21 

12| 

14! 

6 

12 

380 

4 

750 

7,500 

28 

21 

16 

164 

8 

154 

560 

5 

1,000 

10,000 

32 

24 

18 

18 

10 

18 

901 

6 

1,500 

15,000 

364 

28 

20^ 

21 

12 

204 

968 

7 

3,000 

30,000 

49 

37 

25 

26 

15 

23 

1,918 

8 

4,500 

45,000 

60 

50 

29 

32 

20 

29 

2,884 

9 

6,000 

60,000 

72 

54 

36 

40^ 

24 

33 

4,533 

10 

10,000 

100,000 

96 

72 

36 

484 

30 

39 

7,985 

STATION-METERS. 


121 


FIG.  25.— Dial  of  Rotary  Meter. 


CHAPTER  X. 
HOLDERS. 

ALL  holders  should  be  periodically  inspected  for  leaks,  both 
gas  and  water.  The  crown  sheets  of  holders  are  so  constructed 
with  calking  edges  as  to  be,  in  most  instances,  readily  repaired. 
For  leaks  in  the  holder-tank  a  daily  scattering  on  the  surface  of 
the  water  of  a  mixture  of  half  Portland  cement  and  half  very 
fine  coke  ashes,  say  generator  screenings,  will  be  found  to  take 
up  the  majority  of  small  leaks. 

The  carriages  of  all  holders  should  be  frequently  inspected,  and 
immediately  adjacent  to  them  should  be  outlets  and  connections 
for  steam-hose,  having  steam  connection  with  the  works.  This 
steam  should  also  be  connected  to  the  drips. 

Pressure. — In  case  it  is  necessary  to  increase  the  gas  pressure 
upon  the  town,  it  is  frequently  necessary  to  weight  the  holder. 
The  writer  has  found  for  this  purpose  old  railroad  T  rails  (60-ft. 
lengths)  or  I  beams  and  channel-bars  to  be  excellent,  inasmuch 
as  they  give  an  even  distribution  of  weight  over  a  considerable 
surface  and  are  easily  handled,  besides  which,  using  them  as 
units,  an  equal  balance  of  weight  can  be  effected  by  placing  them 
radially  to  the  center  of  the  holder. 

A  table  of  the  weights  of  gas-holders  in  pounds  for  every  one- 
tenth  of  an  inch  maximum  pressure  required,  from  20  to  200  ft. 
in  diameter,  is  given  on  page  123. 

Holder  Pressure. — To  obtain  the  pressure  which  a  gas-holder 
will  throw,  take  the  weight  of  holder  in  pounds,  divide  by  the 
diameter  squared,  multiply  by  0.4091,  which  will  equal  the  pres- 
sure thrown  in  tenths  of  an  inch,  or 


The  relief-holder  acts  largely  as  a  governor  in  producing  an 
even  flow  of  gas  from  the  cupolas  through  the  purifying  appa- 
ratus and,  therefore,  is  an  indispensable  adjunct  to  water-gas 
equipment.  As  the  flow  of  gas  is  intermittent  from  the  machines, 

122 


HOLDERS. 


123 


the  relief-holder  serves  as  an  equalizer,  enabling  the  gas  to  flow 
in  a  continuous  stream  from  its  outlet,  varying  but  slightly  from 
one  period  to  another. 


WEIGHTING  OF  GAS-HOLDERS. 


Diajneter  of 
Gas-holder 
in  Feet. 

Weights  in 
Lbs.  for  each 
0.1  of  an  Inch 
Gas  Pressure. 

Diameter  of 
Gas-holder 
in  Feet. 

Weights  in 
Lbs.  for  each 
0.1  of  an  Inch 
Gas  Pressure. 

Diameter  of 
Gas-holder 
in  Feet. 

Weights  in 
Lbs.  for  each 
0.1  of  an  Inch 
Gas  Pressure. 

20 

164 

64 

1,676 

108 

4,772 

21 

181 

65 

1,729 

109 

4,861 

22 

198 

66 

1,782 

110 

4,950 

23 

217 

67 

1,837 

111 

5,041 

24 

236 

68 

1,892 

112 

5,132 

25 

256 

69 

1,948 

113 

5,224 

26 

277 

70 

2,005 

114 

5,317 

27 

298 

71 

2,062 

115 

5,410 

28 

321 

72 

2,121 

116 

5,505 

29 

344 

73 

2,180 

117 

5,630 

30 

368 

74 

2,240 

118 

5,696 

31 

393 

75 

2,301 

119 

5,793 

32 

419 

76 

2,363 

120 

5,891 

33 

446 

77 

2,426 

121 

5,990 

34 

473 

78 

2,489 

122 

6,089 

35 

501 

79 

2,553 

123 

6,189 

36 

530 

80 

2,618 

124 

6,290 

37 

560 

81 

2,684 

125 

6,392 

38 

591 

82 

2,751 

126 

6,495 

39 

622 

83 

2,818 

127 

6,598 

40 

655 

84 

2,887 

128 

6,703 

41 

688 

85 

2,956 

129 

6,808 

42 

722 

86 

3,026 

130 

6,914 

43 

757 

87 

3,097 

131 

7,021 

44 

792 

88 

3,168 

132 

7,128 

45 

828 

89 

3,241 

133 

7,237 

46 

866 

90 

3,314 

134 

7,346 

47 

904 

91 

3,388 

135 

7,456 

48 

943 

92 

3,463 

136 

7,567 

49 

982 

93 

3,538 

137 

7,678 

50 

1,023 

94 

3,615 

138 

7,791 

51 

1,064 

95 

3,692 

139 

7,904 

52 

1,106 

96 

3,770 

140 

8,018 

53 

1,149 

97 

3,849 

141 

8,133 

54 

1,193 

98 

3,929 

142 

8,249 

55 

1,239 

99 

4,010 

143 

8,366 

56 

1,283 

100 

4,091 

144 

8,483 

57 

1,329 

101 

4,173 

145 

8,601 

58 

1,376 

102 

4,256 

146 

8,720 

59 

1,424 

103 

4,340 

147 

8,840 

60 

1,473 

104 

4,425 

148 

8,961 

61 

1,522 

105 

4,510 

149 

9,083 

62 

1,573 

106 

4,597 

150 

9,205 

63 

1,624 

107 

4,684 

200 

16,364 

124  AMERICAN  GAS-ENGINEERING  PRACTICE. 

Freezing  of  Tanks. — The  freezing  up  of  holders  is  a  problem 
requiring  a  good  deal  of  attention  during  the  colder  months  of 
the  year,  and  all  holders  should  be  fitted  at  frequent  points  with 
connections  for  steam-hose,  and  a  main  steam-line  should  be  con- 
nected with  the  works  and  these  outlets  for  instant  service.  A' 
good  form  of  steam-jet  is  proposed  by  the  gas  educational  trustees 
of  the  American  Gaslight  Association,  a  cut  of  which,  slightly 
modified,  is  herewith  inserted  (Fig.  26).  The  only  fittings  needed 
are  a  1-in.  T  and  a  }-in. Xl-in.  (or  better  a  J-in.  Xl-in.)  bush- 
ing. Into  one  of  the  openings  screws  a  f-in.  steam-pipe  threaded 
on  the  inside,  into  which  has  been  screwed  a  plug,  in  the  center 


J£T  fOK   HOLDE1    fWKS  MD  CUPS. 

'  FIG.  26. — Position  of  Circulation  Jet  for  Water  in  Tanks. 

of  which  has  been  drilled  a  hole;  this  plug  should  project  a  little 
past  the  center  of  the  T.  A  piece  of  1-in.  pipe,  about  18  in. 
long  and  offset  about  6  in.,  is  screwed  into  the  other  outlet  of 
the  T.  Another  piece  of  1-in.  pipe,  from  6  to  8  in.  long,  is 
screwed  into  the  side  outlet  of  the  T.  When  placed  in  position 
the  T  is  set  just  above  the  water-line  of  the  holder-tank  or  cup, 
with  its  run  horizontal,  and  the  side  outlet  of  the  T,  into  which 
is  screwed  the  6-  or  8-in.  section,  directed  downward  into  the 
water  and  extending  4  to  5  in.  below  the  water-line,  as  is  also 
the  offset  end  of  the  other  outlet.  When  the  steam  is  turned 
on,  a  jet  issuing  from  the  drilled  orifice  creates  a  vacuum  in  the 
side-outlet  nipple,  and  the  water  rises  in  this  nipple  and  is  blown 
along  with  the  steam  through  the  offset  piece;  thus  this  jet  not 
only  heats  the  water  but  also  induces  a  rapid  circulation  around 
the  cup  of  the  tank,  and  is,  therefore,  more  effective  than  a  jet 
which  merely  blows  steam  into  the  water,  for  water  will  not  freeze 
as  quickly  when  in  motion  as  when  comparatively  at  rest. 


HOLDERS.  125 

V  ^ 

Cleaning  Tanks. — It  is  occasionally  necessary  to  remove  mud, 
muck,  or  other  accumulations  from  the  bottom  of  a  holder,  which 
can  be  most  readily  accomplished  by  the  use  of  a  basket-shovel, 
or  grab-bucket,  swung  on  the  end  of  a  1-in.  pipe.  After  the 
heavier  substance  has  been  removed,  the  remaining  mud  and 
tar  can  be  stirred  up  and  the  solution  pumped  out  and  replaced 
with  clean  water.  Such  stoppages,  when  they  occur  in  the  inlet- 
and  outlet-pipes,  can  be  removed  in  a  like  manner.  Big  tampers 
of  wood  nearly  fitting  the  diameter  of  the  pipe  can  be  used  to 
advantage  to  churn  and  break  away  stoppages  adhering  to  the 
sides,  after  which  the  contents  may  be  flushed. 

In  case  of  a  leak  occurring  in  a  holder-tank,  the  following 
suggestions  have  been  made  by  various  gas-engineers:  Insert 
in  the  water  of  the  tank,  at  a  point  as  near  as  possible  to  the 
aperture,  sawdust,  bran,  barley  sprouts,  or,  better  still,  horse- 
manure.  The  better  way,  where  cracks  are  vertical,  is  to  cement 
them  while  the  tank  is  full  of  water.  Sheets  of  canvas  saturated 
with  coal-tar  can  also  be  let  down  into  the  tank  and  will  be  held 
against  the  aperture  by  the  pressure  of  the  water. 

Patches. — It  sometimes  occurs  that  it  is  necessary  to  put  a 
patch  upon  a  gas-holder  over  a  ragged  hole  in  the  holder-sheet 
too  thin  to  tap  in  a  thread.  A  cut  of  such  work  (Fig.  27)  will 
be  found  on  the  next  page.  It  consists  of  a  sheet  of  iron  or 
steel  of  such  size  and  shape  as  to  extend  with  a  good  wide  lap 
over  the  orifice  to  be  covered.  Oblong  holes,  say  1X&  in., 
with  the  long  axis  at  right  angles  to  the  edge  of  the  plate,  about 
2  in.  apart  and  f  in.  space  between  the  outer  edge  of  the  hole 
and  edge  of  the  plate,  are  to  be  made  around  the  perimeter  of  the 
patch.  The  heads  of  a  sufficient  number  of  J-in.  bolts  should 
be  flattened  until  they  are  only  \  in.  wide.  The  patch  should 
then  be  held  against  the  sheet  over  the  hole,  until  bolt-holes 
are  made  in  the  sheet  to  correspond  to  those  in  the  patch,  the 
first  two  made  being  at  diagonally  opposite  corners.  The  patch 
can  then  be  temporarily  applied  by  keying  it  on  with  the  flattened 
head  bolts  already  prepared,  one  bolt  being  passed  through  each 
corner  and  the  nut  being  screwed  down,  a  washer  having  first 
been  put  on.  Putty  or  white  lead  should  be  smeared  around  the 
edges  of  the  patch  to  stop  the  escape  of  gas  while  the  remaining 
work  is  proceeding.  The  holes  may  be  made  by  means  of  a  breast- 
drill  and  a  rat-tail  file.  When  the  holes  are  all  completed,  the 
patch  should  be  removed,  the  flow  of  gas  being  temporarily  stopped 
by  pressing  over  the  orifice  another  sheet  of  iron,  wet  gunny- 
sacks,  etc.  A  putty  composed  of  equal  parts  of  red  lead  and 
litharge  mixed  in  glycerine  should  be  coated  over  the  patch, 
when  the  patch  should  be  reapplied  and  permanently  bolted. 


126 


AMERICAN  GAS-ENGINEERING   PRACTICE. 


The  hole  around  each  bolt,  before  the  washer  is  finally  applied, 
should  be  filled  in  with  this  putty,  and  a  strand  of  lamp-wicking 
smeared  with  the  preparation  should  be  tied  around  the  bolt 
prior  to  the  application  of  the  washer,  and  finally  the  nut.  These 
washers  should  be  1J  to  1J  in.  in  diameter. 

If  the  hole  is  a  large  one  and  the  pressure  considerable,  means 
must  be  taken  to  apply  the  patch  temporarily  while  the  holes, 


COMKfTfO  PATCH    Olff/t    SfSMfO    HOlf     /* 
•AOLf>£»    3Mf£T      TOO    THl/t  TO    J*f>. 


4- 


aecr.ion  HLOUS  une. 


FIG.  27.— Patching  Rent  in  Holder-sheet. 

etc.,  are  being  drilled.  In  the  case  of  a  crown-sheet  this  can 
be  done  by  simply  laying  the  patch  over  the  hole  and  weighting 
it  down;  but  in  the  case  of  a  side  hole,  eye-bolts  may  be  attached 
to  the  side  of  the  sheet,  and  the  patch  clamped  on  by  means  of  a 
chain  or  rope  running  around  the  holder,  and,  by  the  use  of  block 


HOLDERS.  127 

and  tackle,  tightly  pulled  up  and  cleated.  The  eye-bolts  may  be 
sawed  off  after  the  patch  is  permanently  attached. 

Capacity. — The  ratio  of  holder  capacity  to  daily  consumption 
in  small  works  generally  equals  1  to  1.  In  larger  works  this  ratio 
is  generally  decreased,  some  of  the  larger  plants  of  the  country 
having  only  half  the  storage  capacity  of  their  daily  output.  It  is 
less  necessary  to  have  this  ratio  equal  in  the  case  of  water-gas 
than  in  that  of  coal-gas.  In  both  instances  it  should  depend 
considerably  upon  manufacturing  capacity.  In  no  instance,  how- 
ever, in  the  opinion  of  the  writer,  should  the  minimum  storage 
capacity  exceed  85  per  cent,  of  the  maximum  daily  demand. 

The  wash-water  from  the  condensers  is  sometimes  success- 
fully pumped  to  and  from  the  relief-holder,  thereby  reducing  the 
temperature  of  the  water  and  economizing  the  quantity  used. 

Salt  should  never  be  used  in  holder-cups  for  the  prevention 
of  freezing,  by  reason  of  its  injurious  effect  upon  the  metal  of  the 
holder. 

TO    OBTAIN    WEIGHT    OF    ANY   HOLDER. 

Diameter2  X pressure  in  y^th  inch X 0.4091=  weight  of  holder  in 
pounds. 

TO    OBTAIN    PRESSURE    WHICH   A   HOLDER   WILL  THROW. 

Weight  of  holder  in  Ibs.  -1,1-1 

— ^~ 7 — ovx/%  A™* —  =  pressure  in  xVtn  men. 

Diameter2  X0.4091 

WEIGHT  AND  PRESSURE  OF  HOLDERS. 
W 


areaX5.2r 


TF=PXareaX5.21. 


CALCULATIONS   FOR   HOLDER    PRESSURE. 

Single-Lift  Holders. 

Let   P  be  the  pressure  of  water  column  in  inches; 
W  the  weight  of  holder  in  pounds; 
D   l  '    diameter  of  holder  in  feet. 


If  we  consider  that  the  pressure  changes  with  the  different 
height  of  shell  above  the  water-line,  the  following  formula  will 
have  to  be  observed: 

-  .  (2) 


in  which  S  represents  weight  of  shell  in  pounds; 
H  the  entire  height  of  shell; 

h         "         the  height  of  shell  above  water. 


128  AMERICAN   GAS-ENGINEERING   PRACTICE. 

Two-Lift  Holders. 

If      D=the  diameter  of  inner  lift; 

W= weight  of  the  inner  lift  in  pounds; 
TFi  =     "       "    "    outer  "    "       " 
W2=     "       "    ll    water  in  the  cup  in  pounds; 
$=     "       "  shell  of  inner  lift  in  pounds  ; 
H— height  of  inner  and  outer  lifts,  minus  cup,  in  feet; 
h=     "      above  water. 

Then,  if  only  the  upper  part  is  working, 
0.245  XW 

52-     v 


\j-m.*s  s^rr        i  w.v/^j.^A^2.t.*      ft)  t  ^  nnnoQ?>  i  /o\ 

— ^CK —  — -r^r.,  TT —         r  U.uuy^o/i  I      .      .      \o) 


should  be  used.     If  both  are  working,  the  following  formula  is 
applicable  : 


In  the  last  or  fourth  formula  we  included  the  bottom  ring  of 
the  outer  section,  which  is  not  correct,  but  the  difference  is  so 
small  that  it  would  not  alter  the  result. 

The  pressures  obtained  by  following  the  given  formulas  would 
be  maximum.  •  The  minimum  pressures,  however,  can  be  readily 
calculated  by  deducting  from  the  weight  of  holder,  in  pounds,  the 
tendency  of  the  gas  to  rise,  in  pounds.  For  example,  if  C  would 
represent  the  capacity  of  the  holder  above  the  water-line,  in  cubic 
feet,  S  the  specific  weight  of  gas,  and  A  the  weight  of  one  cubic 
foot  of  air,  we  obtain,  by  using  formula  (1), 

p    0.245  XTF-CX£X4 
D2 

WEIGHT   OF    SNOW    (TRAUTWINE). 

Fresh-fallen  snow  per  cubic  foot,  5  to  12  Ibs. 

Moistened  and  compact  by  rain,  15  to  50  Ibs. 

For  the  reduction  of  wind  pressure  on  a  circular  surface  to  an 
equivalent  plane  area  (such  as  an  arched  roof  or  a  gas-holder) 
Prof.  Rankine       gives  ................  0.5 

M.  Arson  "    ................  0.46 

R.  J.  Hutton  "    ................  0.67 

W.  H.Y.Webber    "    ................  0.5 

Molesworth  "    ................  0.75 

G.  Livesey  "    ................  0.57 

Prof.  Adams  "    ..............  0.7854 


HOLDERS. 


129 


Walmisley 

V.  Wyatt 

Bancroft 

Cripps 

Sir  B.  Baker 


gives. 

<  < 


Trautwine  

Prof.  Kernot    (of    Melbourne    Uni- 
versity) gives 0.5 

FORCE  OF  THE  WIND. 

(O'CONNOR.) 


0.56 

1.0  (October,  1887) 

0.5 

0.3     - 

0.41 

0.5  area  of  section 

0.5    "     "        " 


Velocity. 

Force. 

Miles  per  Hour. 

Feet  per  Second. 

Lbs.  per 
Square  Foot. 

1 

1.47 

.005 

Hardly  perceptible. 

2 

2.93 

.012 

3 

4.40 

.044 

Just  perceptible. 

4 

5.87 

.048 

5 

7.33 

.123 

Gentle,  pleasant  breeze. 

10.0 

.229 

10 

14.67 

.300 

Pleasant,  brisk  gale. 

20.0 

.915 

15 

22.0 

1.107 

20 

29.34 

1.968 

30.0 

2.059 

25 

36.67 

3.075 

Very  brisk  gale.      i 

40.0 

3.660 

30 

44.01 

4.429 

50.0 

5.718 

35 

51.34 

6.027 

High  winds.              > 

40 

58.68 

7.873 

! 

60.0 

8.234 

Hard  gale. 

70.0 

11.207 

50 

73.35 

12.300 

Very  high  winds. 

80.0 

14.638 

60 

88.12 

17.715 

A  storm. 

90.0 

18.526 

100.0 

22.872 

A  great  storm.     > 

110.0 

27.675 

80 

117.36 

31.490 

A  hurricane. 

120.0 

32.926 

130.0 

38.654 

90 

132.02 

39.852 

140.0 

44.830 

100 

146.7 

•  49.200 

150.0 

51.462 

120 

176.04 

70.860 

130  AMERICAN  GAS-ENGINEERING  PRACTICE. 

Paint. — As  a  holder,  purifying-box,  or  gas-machine  paint,  the 
writer,  after  a  number  of  years  of  experiment,  has  obtained  the 
best  results  from  the  Eclipse  graphite  paint  called  "gas-house 
red/'  as  manufactured  by  the  Acme  White  Lead  &  Color  Works. 
This  paint  is  manufactured  of  pure  graphite.  It  possesses  a 
heavy  body  and  attractive  appearance,  and  will  stand  almost 
any  degree  of  temperature  without  cracking  or  scaling. 

Placing  in  commission  holders,  purifying-boxes,  mains,  or 
other  apparatus.  These  should  be  purged  by  expelling  the  air 
which  they  contain  through  a  double  water-sealed  siphon,  at  the 
outlet  of  which  mav  be  a  test  light  which  may  be  operated  with 
immunity  from  explosion. 

Old  paint  and  rust  should  first  be  removed  from  a  holder 
before  re-painting,  by  the  use  of  wire  brushes  or  scrapers,  or, 
better  still,  by  a  sand-blast. 

Locating  a  site  for  a  holder  should  be  a  matter  of  the  most 
careful  consideration.  Other  conditions  being  satisfactory,  a  first 
test  should  consist  of  making  a  boring  in  the  ground  with  an  earth 
auger  to  a  depth  of  20  ft.  and  recording  the  character  of  the  soil 
as  the  borings  are  brought  to  the  surface.  The  second  test  should 
be  the  weighting  of  a  square  foot  of  the  ground  (at  a  number  of 
places  to  obtain  a  general  average)  with  a  load  of  from  2500  to 
3000  Ibs.,  being  balanced  upon  a  short  piece  of  12X12  timber 
(standing  on  end).  Before  the  load  has  been  applied,  take  the 
elevation  of  the  top  of  the  timber  with  regard  to  a  bench-mark, 
then  immediately  after  the  application  of  the  weight,  continuing 
to  note  the  amount  of  settlement,  until  same  apparently  ceases. 
Then  by  subtracting  the  last  elevation  from  the  first,  the  total 
settlement  can  be  ascertained,  together  with  the  sustaining  quality 
of  the  ground,  from  which  data  the  character  of  the  foundation 
necessary  may  be  intelligently  determined. 

Piling  should  be  avoided  wherever  possible,  and  only  re- 
sorted to  where  piles  can  conveniently  reach  to  bed-rock,  and 
where  marshy  soil  or  quicksand  is  encountered  it  is  invariably 
ultimately  cheaper  to  procure  another  or  different  site.  The 
Stacey  Manufacturing  Co.  cite  a  recent  instance  of  a  holder  of 
about  1,500,000  cu.  ft.  capacity,  erected  upon  soft  ground  at  a  cost 
for  piling  of  75  cents  per  square  foot,  over  the  whole  area  of  same. 
These  piles  were  capped  by  two  feet  of  concrete,  composed  of  good 
Portland  cement,  clean  coarse  sand  and  broken  stone;  but  the 
foundations  failed  immediately  upon  the  filling  of  the  holder  tank 
with  water. 


CHAPTER  XI. 
DETAILS  OF  WORKS  OPERATION. 

ALL  valves  about  works,  mains,  or  pipe  systems  should  be 
distinctly  marked  "open"  or  "shut,"  with  arrow  marking  direc- 
tion of  rotation;  generally  some  one  valve,  right-hand  or  left- 
hand,  should  be  universally  adopted  to  prevent  confusion,  and 
when  so  adopted  there  should  be  no  exception  to  this  rule. 

There  can  be  no  doubt  that  the  standard  of  gas  service  for 
the  future,  maintained  either  by  municipal  legislation  or  by  the 
gas-engineer,  will  be  based  upon  the  calorific  value  of  the  gas. 
This  may  be  ascertained  in  two  ways:  first,  by  analysis  of  the 
gas  and  by  the  addition  of  the  heat  values  of  its  constituent  factors; 
secondly,  by  the  direct  use  of  calorimeters.  There  are  several 
types  of  this  instrument,  of  which  the  Junker  is  perhaps  in  most 
general  use.  Another  in  common  use  in  England  is  that  named 
Simmance  and  Abady.  A  recording  instrument  has  recently  been 
patented  by  F.  N.  Speller.  The  subject  of  the  measurement  of 
temperatures  has  been  best  treated  by  Le  Chatelier  and  Boudouard 
of  Paris,  of  whose  work  there  is  an  excellent  English  translation. 

Where  the  Jones  jet  photometer  is  used  to  check  the  candle 
power  at  the  works  it  should  be  placed  in  such  a  position  that 
the  temperature  will  be  as  nearly  as  possible  constant.  As  the 
readings  depend  principally  upon  the  specific  gravity  of  the 
gas,  they  may  vary  by  reason  of  temperature.  It  should  be 
periodically  standardized  against  a  bar  photometer  and  its  value 
noted.  This  should  occur  at  no  greater  interval  than  once  a 
week  where  it  is  used  to  indicate  actual  candle  power.  Its  prin- 
cipal use  is  a  check  upon  works  operation. 

The  reading  of  water-gages  may  be  done  more  accurately  and 
the  meniscus  more  clearly  defined  by  dropping  into  the  water  a 
small  portion  of  cochineal,  mixed  in  hot  water,  which  is  first 
filtered  and  the  color  fixed  by  the  addition  of  a  few  drops  of  nitric 
acid. 

131 


132  AMERICAN  GAS-ENGINEERING  PRACTICE. 

The  following  readings  should  be  taken  daily  in  every 
works : 

1.  Temperature  of  air  (average  atmospheric). 

2.  Average  barometric  pressure. 

3.  Photometer  and  calorimeter  reading  of  the  gas. 

4.  Temperature   of  gas   at  each  stage  of  manufacture,   con- 
densation, scrubbing,  purification,  etc. 

5.  Hourly  temperature  of  gas  passing  through   station-meter. 

6.  Pressure  of  gas  throughout  every  point  in  the  works  and 
on  the  town,  the  latter  being  recorded  mechanically. 

7.  Purifiers  changed. 

8.  Records  of  test  for  sulphur  at  inlet  and  outlet  of  purifiers. 

9.  Test-cards  from  sight-cocks  on  superheater,  showing  traces 
of  either  tar  or  lampblack,  or  probably  fixed  oil. 

10.  Gas  on  hand  in  holders. 

11.  Oil  on  hand  in  tanks. 

12.  Tar  on  hand  in  tanks. 

13.  Coke  or  coal  used. 

14.  Oil  used. 

15.  Percentage  of  ash  or  screenings. 

16.  Station-meter  indexed. 

17.  Air-meter  indexed. 

18.  Average  pressure  of  gas  through  station-meter  (mechanic- 
ally registered). 

19.  Differential    pressure    or    resistance    of    station-meter    at 
maximum  load. 

20.  Average  gallons  oil  and  pounds  of  generator  fuel  used 
per  1000  cu.  ft.  manufactured. 

The  Green  fuel-economizer  is  a  special  device  for  heating  feed- 
water,  the  apparatus  consisting  of  a  coil  of  pipes  with  an  auto- 
matic scurfing  device,  through  which  the  waste  gases  of  the 
superheater  pass.  Experiments  show  that  these  gases  enter  the 
economizer  at  a  temperature  of  about  1500  deg.  F.,  and  leave  it 
at  between  400  and  700  deg.  Through  the  heat  thus  absorbed  the 
feed-water  is  enabled  to  enter  the  boiler  at  350  deg.,  effecting  a 
considerable  saving  of  boiler  fuel.  The  only  objection  to  this 
apparatus  is  the  rather  considerable  cost  of  installation  in  the 
case  of  small  works,  the  arrangement  being  particularly  fortu- 
nate where  gas  and  electric  works  are  combined  and  the  steam 
production  amounts  to  a  large  portion  of  the  total  manufacturing 
cost.  At  the  present  time  the  Green  Economizer  Company  are  at 
work  on  another  type  of  generator,  with  which  they  will  preheat  the 
blast  air,  permitting  it  to  enter  the  retorts  at  a  temperature  of 
about  400  deg.,  and  effecting  not  only  a  saving  from  6  to  8  per 
cent,  in  generator  fuel,  but  a  very  considerable  saving  in  the  de- 


DETAILS  OF  WORKS  OPERATION.  133 

terioration  caused  by  the  chill  to  the  checker  brick  of  the  other 
two  retorts. 

Where  large  valves  are  frequently  used  and  are  important  in 
their  nature  they  should  be  surrounded  by  manholes  properly 
covered  to  facilitate  repairs  and  render  them  easy  of  access. 

Flow  of  Water. — Great  loss  is  sustained  about  works,  offices, 
etc.,  by  the  leaking  of  various  water  fixtures,  due  to  a  failure 
on  the  part  of  valves  to  properly  seat,  and  the  water  escaping 
therefrom,  often  without  possibility  of  detection,  through  -drains 
and  sewers.  The  following  paragraph  and  table  are  taken  from 
a  paper  written  by  W.  L.  Calkins,  hydraulic  engineer: 

"Few  people  have  even  an  approximate  idea  of  the  quantity 
of  water  which  may  be  wasted  through  small  openings,  and  for 
this  reason  I  give  the  following  table,  which  gives  the  number 
of  gallons  of  water  discharged  through  various  small  openings 
in  24  hours,  under  a  pressure  of  60  Ibs.  per  square  inch: 

Diam.  of  Orifice,  Inch.  Gallons. 

& 61 

& 230 

A 907 

t 3,649 

} 14,616 

| 32,558  '2 


PART  II. 

GAS  DISTRIBUTION. 


CHAPTER  XII. 
NAPHTHALENE. 

NAPHTHALENE  is  a  hydrocarbon  formed  in  comparatively 
small  quantity  (about  13.15  Ibs.  per  ton  of  ordinary  English  coal 
distilled  in  coal-gas  retorts,  according  to  R.  W.  Irwin)  during 
the  distillation  at  high  temperatures  of  carbonaceous  substances 
such  as  coal  and  petroleum.  It  has  been  claimed  that  naphtha- 
lene can  be  formed  in  the  gas  after  it  leaves  the  retorts  and  during 
distribution,  but  this  view  is  generally  held  to  be  incorrect,  and 
from  the  present  knowledge  of  the  subject  it  seems  practically 
certain  that  all  of  the  naphthalene  found  either  in  coal-gas  or 
coal-tar  is  produced  during  the  distillation  of  the  coal  in  the  re- 
torts. The  molecule  of  naphthalene  is  composed  of  10  atoms 
of  carbon  and  8  atoms  of  hydrogen,  its  chemical  symbol  being 


Properties.  —  It  is  a  solid  at  ordinary  temperatures  and  pres- 
sures, melting  at  a  temperature  of  176°  F.  It  will,  however,  exist 
in  a  state  of  vapor  suspended  in  gas  at  temperatures  far  below 
even  that  at  which  it  solidifies  as  long  as  the  gas  is  not  saturated 
with  it.  As  soon  as  the  point  of  saturation  is  reached  the  vapor 
passes  directly  into  the  solid  state  in  the  form  of  very  light,  flaky, 
flat  crystals  which  occupy  a  large  volume  in  proportion  to  their 
weight.  It  is  this  property  which  renders  naphthalene  so  trouble- 
some to  the  gas-manufacturer,  since,  though  the  weight  contained 
in  a  given  quantity  of  gas  is  small,  the  crystals  occupy  sufficient 
space  to  seriously  obstruct  the  apparatus  and  pipes  around  the 
works  and  the  services  in  which  they  are  deposited  through  chill- 
ing of  the  gas. 

135 


136  AMERICAN  GAS-ENGINEERING  PRACTICE. 

Naphthalene  obstructions  in  the  apparatus  and  pipes  at  the 
works  are  usually  removed  either  by  flushing  with  hot  water 
or  by  steaming,  the  former  being  preferable  since  the  steam  merely 
melts  the  naphthalene,  and  unless  it  can  escape  from  the  pipe 
at  once  it  may  cool  down  again  and  solidify  in  another  part  of 
the  apparatus,  while  the  hot  water  acts  not  only  by  melting  the 
naphthalene,  but  also  by  carrying  it  along  to  a  certain  extent  in 
mechanical  suspension.  It  is  well  to  use  the  water  in  consider- 
able volume  in  order  to  secure  this  latter  effect. 

Naphthalene  is  removed  from  service-pipes  and  small  mains 
by  means  of  light  naphtha,  gasoline,  or  kerosene,  which  is  poured 
into  and  allowed  to  run  through  the  pipes,  dissolving  the  crystals 
and  carrying  the  naphthalene  in  a  liquid  form  back  into  the 
mains  and  drips.  Sometimes  wood-alcohol  is  used  instead  of 
naphtha  or  kerosene.  If  the  obstruction  is  very  light  it  may  be 
blown  out  of  the  service  into  the  main  by  means  of  an  air-pump, 
or  even  by  the  lungs. 

Naphthalene  in  the  form  of  crystals,  like  water  in  the  form 
of  ice  or  snow,  will  pass  from  the  solid  state  directly  into  that 
of  vapor,  and  thus  naphthalene  that  has  been  deposited  in  the 
pipes  hi  quantities  too  small  to  cause  trouble  and  render  it  necessary 
to  clean  it  away  will  evaporate  again  and  pass  off  with  the  gas 
when  this  reaches  the  deposit  in  an  unsaturated  condition.  This 
same  naphthalene  may  be  redeposited  further  along  in  the  sys- 
tem if  the  temperature  changes  so  as  to  bring  the  gas  tempera- 
ture again  to  the  point  of  saturation  with  naphthalene,  and  it  is 
probable  that  some  action  of  this  kind  has  given  rise  to  the  theory 
that  naphthalene  can  be  formed  during  distribution  in  a  gas 
which  was  free  from  it  when  it  left  the  holders. 

Deposits. — Accumulations  of  naphthalene  in  the  inlet-pipes  of 
gas-holders  occur  most  frequently  in  that  portion  of  the  pipe 
which  passes  down  under  the  tank-wall  and  up  inside  the  holder. 
When  naphthalene  exists  in  the  pipe  as  a  flocculent  lining  of 
approximately  uniform  thickness  throughout  a  large  portion  of 
its  length,  it  can  be  removed  by  charging  the  gas  with  the  vapor 
of  light  naphtha,  gas  so  charged  being  able  to  pick  up  naphtha- 
lene deposited  in  the  form  of  loose  crystals.  The  gas  can  be 
charged  with  the  vapor  either  by  injecting  the  naphtha  into  the 
inlet-pipe  in  the  form  of  a  spray,  by  means  of  a  steam-jet,  or  by 
filling  the  drip  at  the  bottom  of  the  pipe  with  naphtha,  which 
gradually  evaporates  into  the  gas  passing  over  it.  Naphthalene 
in  the  condition  named  can  also  be  removed  by  blowing  steam 
into  the  pipe  in  sufficient  quantity  to  raise  the  temperature  to 
the  point  at  which  the  naphthalene  will  either  melt  and  run  down 
into  the  drip,  from  which  it  can  be  pumped  out,  or  vaporize  and 


NAPHTHALENE.  137 

be  taken  up  by  the  gas.  In  all  of  these  methods  it  is  necessary 
to  have  gas  flowing  through  the  pipes,  so  that  the  naphthalene 
as  it  is  vaporized  will  be  picked  up  by  the  gas  and  carried  along 
with  it  out  of  the  pipe,  and  there  is  always  danger  that  the  naph- 
thalene so  picked  up  will  be  again  deposited  at  an  inconvenient 
point  during  the  further  travel  of  the  gas.  When  naphtha  vapor 
is  employed  this  will  condense  at  the  same  time  that  the  naph- 
thalene is  deposited,  dissolve  the  latter,  and  carry  it  along  to  the 
nearest  drip,  thus  preventing  any  obstruction,  but  when  steam 
is  used  the  liability  is  great  that  the  obstruction  will  be  merely 
transferred  from  one  point  of  the  pipe  system  to  another. 

In  many  cases  the  presence  of  naphthalene  is  not  suspected 
until  it  has  formed,  on  the  inside  of  the  portion  of  the  pipe  which 
rises  through  the  water  in  the  tank,  a  layer  of  such  thickness 
that  it  is  detached  from  the  sides  of  the  pipe  by  its  own  weight 
and  falls  into  the  elbow  making  the  turn  from  the  vertical  into 
the  horizontal  part  running  under  the  tank-wall,  where  it  forms 
a  compact  mass.  Such  a  mass  seems  to  be  very  little  affected 
by  heat  or  with  naphtha  in  the  liquid  form.  Hot  water  may  be 
used  in  several  ways.  At  one  works,  the  water,  heated  by  means 
of  steam  in  an  old  boiler  equipped  for  the  purpose,  the  pressure 
being  run  up  to  between  thirty  and  forty  pounds  per  square  inch, 
was  conducted  to  the  holder  by  a  temporary  line  of  pipe. 

Removing  Deposits. — The  operation  of  cleaning  out  the  holder- 
inlet  was  carried  on  as  follows :  The  holder  was  practically  emptied 
of  gas,  the  time  chosen  being  that  when  the  stock  of  gas  was 
small  enough  to  be  contained  in  the  other  holders,  and  kept  so 
as  long  as  possible,  though  this  was  merely  to  keep  the  weight 
of  pipe  to  be  handled  at  a  minimum,  as  the  holder  could  be  raised 
through  the  outlet-pipe  without  interfering  with  the  work. 
Through  a  hole  drilled  in  the  top  of  the  bonnet  over  the  inlet- 
pipe  was  inserted  a  one-inch  pipe  on  the  bottom  of  which  was 
screwed  a  1 X 1  in.  L,  the  direction  in  which  this  L  pointed  being 
marked  on  the  pipe  at  the  top.  This  pipe  was  made  long  enough 
at  the  start  to  reach  down  to  the  bottom  of  the  holder-inlet,  and 
a  number  of  short  pieces  of  pipe  were  provided  to  screw  on  as 
the  holder  rose.  The  pipe  fitted  loosely  in  the  hole  in  the  bon- 
net, but  a  practically  gas-tight  joint  was  made  by  wet  cloths 
wound  round  the  pipe  at  this  point.  The  pipe  was  supported 
and  turned  by  means  of  a  bar  handle  clamped  on  at  the  proper 
height.  A  hose  connection  being  made  between  this  pipe  and 
that  from  the  hot-water  heater,  and  the  water  being  turned  on, 
it  issued  from  the  opening  in  the  L  in  a  jet  which  broke  up  and 
dissolved  the  naphthalene  and  ran  down  into  the  drip,  from  which 
it  was  pumped,  bringing  the  naphthalene  with  it  both  in  solu- 


138  AMERICAN  GAS-ENGINEERING  PRACTICE. 

tion  and  in  suspension.  The  drip-pump  was  kept  working  all 
the  time  the  hot  water  was  being  run  in,  so  that  the  water  should 
be  pumped  out  before  it  cooled  down  and  dropped  the  naphtha- 
lene. The  water-pipe  being  turned  so  that  the  stream  played 
against  all  parts  of  the  inlet-pipe,  a  very  complete  cleaning  could 
be  given  by  this  method. 

Another  method  of  washing  out  the  naphthalene  is  called 
"plunging."  In  this  the  inlet-pipe  is  sealed  with  water,  the 
flange  at  the  top  of  the  vertical  pipe  outside  the  holder  taken 
off,  and  the  drip-pump  removed.  The  pipe  is  then  rilled  as  full 
of  hot  water  as  it  is  possible  to  have  it  without  filling  up  the 
horizontal  run  coming  to  the  holder  from  the  station-meter.  A 
plunger  or  wooden  cylinder,  about  18  inches  to  2  feet  long  and 
a  little  smaller  in  diameter  than  the  pipe,  fastened  to  a  pipe  handle, 
the  axes  of  the  pipe  and  the  cylinder  coinciding,  is  then  inserted 
and  worked  up  and  down,  so  as  to  impart  a  surging  motion  to 
the  whole  body  of  water.  The  surging  back  and  forth  of  the  water 
dislodges  the  naphthalene  that  is  not  dissolved,  and  the  large 
pieces  rising  to  the  surface  are  fished  out,  the  remaining  fine  par- 
ticles being  pumped  out  with  the  water.  It  is  rather  a  difficult 
matter  to  get  the  large  body  of  water  contained  in  pipes  above 
6  in.  in  diameter  moving  with  sufficient  velocity  to  dislodge  the 
compact  masses  of  naphthalene;  but  if  the  motion  can  be  produced, 
"plunging"  is  a  very  effective  method  for  the  removal  of  naph- 
thalene from  the  pipes. 

When  naphtha  or  any  other  liquid  solvent  is  used  it  is  not 
economical  to  pour  it  into  the  pipe  by  itself,  since  if  this  is  done 
it  will  cut  channels  in  the  deposit,  through  which  it  will  run  to 
the  drip  before  it  is  fully  saturated  with  naphthalene.  A  better 
effect  can  be  obtained  by  pouring  water  into  the  inlet  until  it 
is  filled  to  half  its  height.  Then  from  four  to  five  gallons  of  sol- 
vent naphtha  are  poured  in  and  the  water  slowly  pumped  out 
at  the  drip,  so  that  the  liquid  gradually  falls  in  the  main.  The 
consequence  is  that  the  solvent,  which  forms  a  layer  on  the  top 
of  the  water,  is  forced  to  act  on  the  whole  of  the  interior  surface 
of  the  main,  both  where  the  latter  is  upright  and  where  it  is  nearly 
horizontal.  The  time  during  which  it  acts  on  the  surface  is  deter- 
mined by  the  rate  of  pumping,  and  thus  may  be  made  sufficiently 
long  to  complete  the  solution  of  the  naphthalene.  When  the 
solvent  has  reached  the  elbow,  the  rate  of  pumping  is  diminished 
in  order  to  give  it  time  to  act  on  the  greater  horizontal  section 
of  the  pipe  which  then  becomes  exposed  to  it.  By  this  method 
of  treatment  the  whole  of  the  inner  surface  of  the  pipe  is  freed 
from  naphthalene,  which  is  completely  removed  from  the  main 
through  the  pumps. 


NAPHTHALENE.  139 

Preventing  Deposits. — The  various  methods  employed  or 
proposed  to  prevent  the  deposition  of  naphthalene  in  a  solid  state 
in  the  mains  and  services  may  be  divided  into  two  general  classes, 
those  which  remove  the  naphthalene  from  the  gas  at  the  works 
by  means  of  some  absorbent,  and  those  which  consist  in  add- 
ing to  the  gas-vapors  of  liquids  having  a  solvent  action  on  naphtha- 
lene and  approximately  the  same  vapor  tension  as  that  sub- 
stance. 

Methods  of  the  first  class  have  been  adopted  quite  generally 
on  the  continent  of  Europe  and  to  some  extent  in  Great  Britain. 
In  them  the  gas  is  washed  or  scrubbed  with  an  oil  which  possesses 
the  property  of  absorbing  naphthalene  vapor,  the  process  being 
exactly  similar  to  that  by  which  the  ammonia  is  removed  from 
the  gas.  The  operation  is  usually  carried  on  in  a  rotary  mechanical 
scrubber  of  the  Standard  type,  in  which  either  creosote-oil, 
heavy  tar-oil,  or  anthracene-oil  is  used  instead  of  water.  A  small 
amount  of  benzol,  from  4  to  8  per  cent,  by  weight,  is  added  to  the 
oil  used,  to  saturate  it  and  thus  prevent  it  from  absorbing  benzol 
from  the  gas  and  reducing  the  illuminating  power. 

According  to  Dr.  Bueb  at  Dessau,  Germany,  an  anthracene-oil 
boiling  between  480°  and  750°  F.  is  used,  and  176.4  Ibs.  (19  to  20 
gallons)  of  this  oil  removed,  from  706,000  cu.  ft.  of  gas,  naphtha- 
lene to  the  amount  of  about  200  grains  per  1000  cu.  ft.  The 
capacity  of  the  oil  for  naphthalene  increases  with  the  tempera- 
ture, and  the  naphthalene  scrubber  should  follow  the  tar-extractor 
and  work  on  comparatively  hot  gas.  In  some  cases,  however, 
two  or  three  compartments  of  the  ammonia  scrubber  are  used. 
After  being  saturated  with  naphthalene  the  oil  can  be  put  in  a 
still  and  the  naphthalene  driven  off,  or  it  can  be  chilled,  crys- 
tallizing the  naphthalene,  which  is  then  removed  by  means  of  a 
filter-press.  In  either  case  the  oil  can  be  used  over  again.  If 
working  on  a  small  scale,  it  may  be  more  economical  to  run  the 
saturated  oil  into  the  tar-tank  and  sell  it  as  tar. 

The  frequently  employed  method  of  running  into  the  gas,  as 
it  goes  out  into  the  district,  naphtha  which  becomes  vaporized 
and  travels  along  with  the  gas,  belongs  to  the  second  class.  The 
naphtha  is  usually  added  to  the  gas  at  the  outlet  of  the  governor, 
being  blown  into  the  gas  in  a  finely  divided  spray  by  a  small 
steam-jet  atomizer.  The  success  of  this  method  depends  upon 
the  precipitation  of  the  naphtha  in  liquid  form  at  the  time  and 
place  at  which  the  naphthalene  is  deposited,  so  that  the  latter 
will  be  dissolved  and  carried  off  by  the  former,  and  as  this  does 
not  always  occur  the  remedy  is  not  always  successful. 
J  A  modification  of  the  above  method,  known  in  English  as  the 
Hastings  carburation  process,  consists  in  forming  in  the  gas  as 


140  AMERICAN  GAS-ENGINEERING  PRACTICE. 

it  goes  out  from  the  works  into  the  street-mains  a  mist  of  oil, 
the  oil  used  being  one  that  is  not  volatile  at  ordinary  tempera- 
tures. This  mist,  in  very  minute  drops,  is  formed  by  blowing 
the  oil  through  specially  constructed  atomizers  by  means  of  a 
portion  of  the  gas,  which  is  compressed  to  a  pressure  of  75  Ibs. 
per  square  inch.  It  is  found  that  in  this  state  of  minute  sub- 
division some  of  the  oil  will  remain  in  the  gas  until  it  reaches 
the  farthest  point  in  the  district;  the  conditions  which  will  cause 
the  deposition  of  naphthalene  at  any  point  will  also  precipitate 
enough  of  the  oil  to  dissolve  this  naphthalene  and  carry  it  off  as 
a  liquid.  It  is  stated  that  at  Hastings  one  gallon  of  oil  used  in 
this  way  for  each  166,000  cubic  feet  of  gas  is  sufficient  to  do  away 
with  all  trouble  from  naphthalene  stoppages,  although  these  begin 
to  show  as  soon  as  the  process  is  discontinued. 

Much  information  on  the  subject  of  prevention  of  deposits 
of  naphthalene  in  street-mains  and  services  can  be  found  in  Vols. 
LXXII  to  LXXVI  of  the  Journal  of  Gas-lighting. 

According  to  Dr.  Paul  Eitner,  in  the  Journal  fur  Gasbeleuch- 
tung,  Vol.  42,  p.  89, 

One  gram  of  benzine  will  dissolve 

0.32  grams  of  naphthalene  at 32°  F. 

0.407  grams  of  naphthalene  at 50°  F. 

From  tables  of  the  vapor  tensions  of  benzine  and  naphthalene 
it  is  found  that 

One  cubic  foot  of  gas  can  take  up 

3.25  grams  of  benzene  at 32°  F. 

5.72  grams  of  benzene  at 50°  F. 

9.45  grams  of  benzene  at 70°  F. 

One  cubic  foot  of  gas  can  take  up 

0.0005  grams  of  naphthalene  at 32°  F.     i 

0.0045  grams  of  naphthalene  at 50°  F. 

0.0155  grams  of  naphthalene  at 70°  F. 

These  figures  show  that  gas,  if  saturated,  can  carry  2000  times 
as  much  benzene  as  would  be  required  to  dissolve  the  largest 
amounts  of  naphthalene  the  gas  can  hold  at  32°  F. 

Oil-tar,  after  being  separated  from  oil  and  entrained  water, 
is  suggested  as  a  remedy  for  naphthalene,  the  gas  being  scrubbed 
through  it  in  the  same  manner  as  with  anthracene  oil,  when 
it  will  absorb  about  25  per  cent,  of  its  own  bulk  of  naphtha- 
lene.. 


NAPHTHALENE. 


141 


A  Continuous  Naphthalene  Test  may  be  arranged  as  follows: 

Dissolve  150  grains  picric  acid  in  one 
quart  warm  distilled  water.  Bubble  1  ft. 
to  1J  ft.  gas  per  hour  through  100  c.c.  of 
this  solution.  If  gas  contains  an  excess 
of  naphthalene,  a  heavy  precipitate  will 
appear.  Avoid  use  of  rubber  tubing 
in  making  test. 

If  gas  contains  tar,  filter  through  a 
tube  containing  cotton.  Tar  will  color 
solution  brown  and  prevent  naphthalene 
precipitate  forming. 

If  gas  contains  an  excess  of  ammonia 
— say  more  than  5  grains — bubble  gas 
first  through  5  per  cent  sulphuric-acid 
solution.  Ammonia  will  color  the  acid 
red-brown  and  prevent  precipitation. 
One  or  more  of  the  absorption  bottles  like 
that  represented  in  Fig.  28  may  be  used. 


FIG.  28. 


CHAPTER  XIII. 
MAINS. 

Capacity. — The  gas-consumer  is  connected  with  the  gas-supply 
in  the  works  holder  by  underground  pipes  or  mains  with  their 
branches  and  service-pipes.  These  pipes  are  generally  of  cast 
iron,  although  in  the  natural-gas  districts  steel  screw-joint  pipe  is 
largely  used,  and  the  connections  to  services  are  made  by  tapping 
into  the  top  or  side  as  preferred.  The  formula  for  calculating 
the  capacity  of  cast-iron  mains  was  given  by  Clegg  and  attributed 
to  Pole,  being  known  as  Pole's  formula,  and  is  stated  as  follows: 


™  -  gl 

where  V= cubic  feet  delivered  per  hour  into  atmospheric  pressure; 

d  =  internal  diameter  of  the  pipe  in  inches; 

h  =  pressure  on  gas  at  entrance  in  inches  of  water-head; 

g= specific  gravity  of  the  gas,  air=l; 

1=  length  of  pipe  in  yards. 

The  constant  1350  is  arrived  at  when  considering  a  fixed  fric- 
tion derived  from  very  old  experiments.  Some  engineers  assume 
this  figure  only  for  pipes  10  in.  or  over  in  diameter,  taking  1250 
for  6-  to  10-in.  pipes  and  1000  for  pipes  under  6  in.  diam.  This 
formula  is  of  course  applicable  to  low-pressure  distribution  only. 
When  higher  pressures  are  employed,  such  as  exist  in  high-pres- 
sure distribution  or  natural-gas  practice,  a  formula  must  be  em- 
ployed taking  into  consideration  both  entrance  and  terminal 
pressures,  influence  of  compression  and  temperature,  such  as  that 
developed  by  Professor  Robinson: 


142 


MAINS.  143 

where  T0  =  461  +37  =  498  deg.  F.,  the  absolute  temperature  at  the 

maximum  density  of  water; 
TI  =  absolute  temperature  of  gas  after  delivery  (461+ deg. 

F.); 

T2  =  absolute  temperature  of  gas  in  the  main; 
d  =  diameter  of  the  pipe  in  inches; 
L=  length  of  main  in  miles; 
pi  =  initial  and 

p2  =  terminal  gage  pressure  in  Ibs.  per  sq.  in.,  and 
g= specific  gravity  of  the  gas  transmitted  (that  of  natural 

gas  being  0.6). 

The  Cox  gas-flow  computer,  a  slide-rule  device,  was  calculated 
from  this  formula: 


=  33.3>|g 


where  PI  and  P^  are  the  initial  and  terminal  pressures  absolute 
(14.7+gage  pressure)  in  Ibs.  per  sq.  in.  A  more  accurate  deter- 
mination by  actual  test  is  made  by  the  Pitot  tube,  described  in 
the  chapter  upon  Pressures.  J,  D.  Shattuck  in  1905  made  a  re- 
port upon  the  various  formulas  for  this  purpose  to  the  Ohio  Gas- 
light Association,  subsequently  published  in  Progressive  Age.  In 
comparing  the  capacities  of  mains  it  is  thus  seen  that  this  varies 
as  the  square  root  of  the  fifth  power  of  the  diameter. 

Laying  Mains. — The  depth  at  which  mains  should  be  laid  should 
depend  upon  two  conditions,  namely,  climate  and  the  protec- 
tion of  mains  from  the  crushing  stress  of  heavy  traffic.  It  is  cus- 
tomary, with  regard  to  climate,  to  place  the  top  of  the  pipe  below 
the  nominal  frost-line,  which  varies  from  6  ft.  in  Canada  to  some 
24  in.  in  the  Southern  States.  For  ordinary  purposes,  however, 
30  in.  below  the  ground  generally  gives  satisfactory  results.  Such 
laying,  however,  depends  somewhat  upon  topography  and  local 
conditions,  such  as  the  presence  of  sewer-lines  and  -services,  water- 
mains,  etc.  It  is  necessary,  of  course,  to  lay  pipe  upon  a  grade 
sufficient  to  completely  drain  it,  and  it  is  economical  and  good 
practice  to  lay  as  long  a  line  as  possible  without  putting  in  drip- 
pots.  As  an  offset,  however,  to  this  is  the  increased  expense  of 
ditching  not  only  in  the  initial  installation,  but  the  subsequent 
laying  of  service-lines. 

The  writer  strongly  advises  that  at  no  time  shall  a  smaller 
size  of  cast-iron  pipe  than  4  in.  diam.  be  laid.  There  are  occa- 
sions where  districts  will  not  require  a  larger  size  than  3  in.  for 
an  indefinite  period,  but  these  are  rare  and  generally  can  be  sup- 
,  plied  by  long  services  of  wrought-iron  pipe. 


144 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


A  good  average  weight  for  4-in.  cast-iron  pipe  is  220  Ibs.  per 
length  of  12  ft.,  or  in  the  neighborhood  of  18  Ibs.  per  ft.  A  lighter 
pipe  than  this  is  not  advised,  as  it  is  impossible  to  anticipate  what 
crushing  stress  it  may  have  to  endure,  to  say  nothing  of  the  ad- 
vantage of  strong  bells  for  calking. 

Specifications  for  various  classes  of  cast-iron  pipe  and  fit- 
tings, as  designed  by  the  Committee  on  Research  for  the  Ameri- 
can Gaslight  Association,  are  appended  to  this  volume. 

Gradient. — The  minimum  grade  permissible  for  draining 
mains  should  certainly  in  no  instance  exceed  one  inch  per  100  ft. 

How  MAWS  SHOULD  BE 


FIG.  I-  CORRECT  P/PE  B EDO  INC  — 


<]\    BELL  HQL£. 


77777: 
BL  0  C  K ING     LoUHTfffSUNK. 


'J 


^BELL HOLE,:  f///f  V/  7  *~^&lfiW3  y^T^^.^m^f'l TT7777\ 

FIG.  z  -  /ncofiRECT  Pi  PE  Betiowe  —  v/ 

BL  oc*//v6  on  TOP  orD/»  7- 
FIG.  29. — Proper  Method  for  Laying  Mains  in  Trench. 

of  main.  This,  however,  is  about  the  minimum  permissible  in  a 
sewer.  Where  a  greater  hydraulic  head  as  well  as  hydraulic 
radius  is  obtained,  the  hydraulic  radius  in  gas-mains  is  so  exceed- 
ingly small  and  the  viscosity  of  the  condensation  (composed 
largely  of  tar  and  other  oily  ingredients)  is  so  great  that  better 
practice  suggests  a  fall  of  at  least  a  quarter  of  an  inch,  or  better 
0.318  in.  per  length  of  12  ft.  of  pipe.  This  is  more  necessary  in 
low-pressure  mains  than  in  high  pressure,  the  latter  having  less 
condensation  and  the  velocity  of  the  gas  tending  to  free  the  main 
from  liquids  collecting  in  trapped  portions. 

Where  the  soil  is  bad  and  shifting,  the  bottom  of  the  ditch 
should  be  blocked.  This  should  be  done  in  any  event  where 
the  size  of  the  pipe  exceeds  18  in.  diam.  These  blocks,  usually 
2X12X20  in.,  should  be  below  the  level  of  the  bed  of  the  ditch, 
as  per  Fig.  29,  th§  whole  surface  presented  to  the  pipe  being 


MAINS.  145 

flush  and  forming  a  continuous  bearing  for  it.  The  same  gra- 
dient or  fall  of  the  pipe  is  maintained  throughout. 

District  mains  should  be  invariably  laid  with  an  allowance 
for  extension  of  business,  and  the  calculation  should  be  based 
upon  a  system,  which,  when  loaded  to  capacity,  would  not  show 
a  pressure  drop  at  the  moment  of  peak-load  in  excess  of  25  per 
cent.,  20  per  cent,  being  better  practice. 

Pipe=joint  Specifications. — The  following  are  the  specifica- 
tions of  the  United  Gas  Improvement  Co.  of  Philadelphia,  for  the 
making  of  lead  joints:  ''Each  spigot  end  should  be  driven  home 
into  the  bottom  of  the  bell,  the  joints  should  be  well  calked  with 
jute  packing,  the  greatest  care  should  be  taken  that  the  packing 
is  calked  as  solid  as  the  yarning-iron  and  heavy  hammer  will 
calk  it.  This  joint  in  itself  should  be  gas-tight.  The  calking 
should  be  done  evenly,  so  that  all  parts  of  the  joint  will  be  evenly 
solid.  The  lead  should  be  of  the  best  quality  of  soft  lead  and 
the  amount  required  per  joint  approximately  as  follows: 

3-in.  pipe  about  2J  Ibs.  lead. 

4-in.  "  "  4  "  " 

6-in.  "  "  1  "  " 

8-in.  "  "  10  "  " 

10-in.  "  "  14  "  " 

12-in.  "  "  18  "  " 

16-in.  "  "  28  "  " 

18-in.  "  "  32  "  " 

20-in.  "  "  35  "  " 

"The  weights  given  above  have  been  found  to  be  sufficient 
if  the  yarning  has  been  properly  done.  The  lead  should  be  evenly, 
gradually,  and  thoroughly  calked,  so  that  when  finished  all  parts 
of  the  joint  will  be  of  an  equal  decree  of  hardness.  In  no  case 
should  a  joint  be  completely  calked  at  one  part  before  the  other 
parts  of  the  joint  are  taken  in  hand. 

"In  layin.s;  mains,  when  it  is  required  to  turn  a  corner,  or  to 
make  a  bend  for  any  purpose,  elbows  or  specials  should  always 
be  used.  It  is  bad  practice  to  make  a  bend  by  making  each 
joint  give  a  little  and  thus  dispensing  with  the  use  of  a  special. 
Quarter  bends  and  eighth  bends  can  be  always  obtained,  and 
special  angles  can  be  made  by  the  use  of  circle  bends.  These 
specials  can  be  cut  so  as  to  obtain  almost  any  required  an^le. 

"Great  economy  will  result  from  the  proper  handling  of  the 
ditch  or  trench  in  which  main  is  to  be  laid.  The  earth,  stone, 
gravel,  etc.,  should  be  separated  upon  being  excavated  with  large 
forks,  each  according  to  its  kind,  and  in  back-filling  should  be  re- 


146  AMERICAN  GAS-ENGINEERING  PRACTICE. 

laid  in  strata,  the  large  stones  first,  then  smaller  stones,  and  finally 
gravel  with  the  dressing  of  loose  earth,  each  stratum  being  sepa- 
rately and  thoroughly  tamped  into  place.  This  back-filling,  when 
properly  done,  will  not  settle  and  leave  a  depression  in  the  street. 
"No  larger  ditch  or  trench  should  be  excavated  than  is  actu- 
ally needful  for  the  size  of  pipe  to  be  laid.  An  approximate  table 
of  the  width  of  a  trench  for  various  sizes  of  pipe  is  herewith  given. 

4-in.  diameter,  width  20  in. 

6-in.  "  "  22  in. 

8-in.  "  "  24  in. 

12-in.  "  "  30  in. 

16-in.  "  "  35  in. 

20-in.  "  "  40  in. 

24-in.  "  "  44  in. 

30-in.  "  "  50  in. 

36-in.  "  56  in. 

In  excavating  the  bottom  of  the  trench  should  be  carefully 
graded  and  bell-holes  made  at  intervals  of  12  feet.  The  bottom 
of  the  ditch  shall  be  such  as  to  give  a  continuous  and  positive 
bearing  for  the  main. 

"In  running  lead  joints,  standard  pipe  being  used,  the  spigot 
end  being  first  rammed  home,  the  space  formed  by  the  junction 
of  the  spigot  and  bell  shall  be  filled  and  calked  with  strands  of 
tarred  oakum  until  the  space  is  filled  to  give  the  lead  depth 
required  for  the  size  of  pipe,  and  driven  up  sufficiently  tight  to 
cause  the  yarning  to  spring  back  when  impinged.  This  lead 
depth  to  be  left  in  the  bell  should  vary  with  different  sizes  of 
pipe  and  should  be  about  as  follows: 

4-in.  diameter  pipe,  lead  joint  to  be  1J  in.  deep. 

£>_:„  ( i  tt         (i         ( (        t  (    i  <.    -1  i    1 1        u 

n  t  i         n         it        i  (    <  i    -i&    i  c        1 1 

.<          li         ..i        M    «    if    ri        „ 

16-in.        "  "       "       "      "   il  2     "      " 

20-in.        "  "       "       "      "   "  21  "      " 

o/i  ;>t  a  it         u         u       it    it  01    <<        " 

^Tt~iii»  ^x 

30-in.        "  "       "       ll      "   "  2J  "      " 

36-in.        "  "       "       "      "   "  2J  "      " 

All  joints  when  run  should  be  flush  with  the  face  of  the  bell, 
and  should  they  be  driven  up  in  calking  more  than  £  in.  they 
should  be  re-run. 

"All  joints  should  be  invariably  tested  before  joint-holes  are 


MAINS.  147 

back-filled.  It  is  best  where  feasible  to  test  long  sections  of  pipe 
by  pumping  up  an  air  pressure,  using  a  pressure-gage  and  noting 
loss  of  pressure  due  to  leakage.  The  test  pressure  should  not  be 
less  than  5  Ibs.  per  sq.  in.  (10  in.  of  mercury).  But  where  this 
method  is  impossible  each  joint  should  be  covered  with  heavy  soap- 
suds while  under  gas  pressure  and  an  examination  made  for 
bubbles. 

"It  sometimes  becomes  necessary  to  use  a  split  sleeve  in  the 
case  of  a  broken  main,  although  its  use  is  to  be  avoided.  When 
used,  however,  it  is  an  invariable  rule  that  the  two  ends  of  the 
pipe  should  be  bound  together  by  wrapping  with  unbleached 
muslin  or  canvas,  a  mixture  of  red  lead  and  white  lead  being 
spread  in  the  folds  of  the  cloth,  the  whole  securely  wrapped  with 
strong  twine  or  cord,  and  coated  with  shellac.  The  width  of 
the  wrapping  should  be  such  that  the  sleeve  projects  on  either 
side  at  least  2  inches.  After  this  is  completed  the  split  sleeve 
is  to  be  applied,  care  being  taken  that  there  should  be  no  leak 
at  the  flanged  joint.  It  is  sometimes  necessary  if  the  flanges 
are  not  faced  that  the  joint  between  them  should  be  made  with 
tar  board  which  has  been  softened  by  soaking  in  warm  water. 
It  is  better,  however,  to  face  them  by  grinding  them  upon  each 
other  with  fine  emery  powder. 

"It  is  well  to  purchase  all  cast  pipe  and  specials  uncoated,  var- 
nished, or  tarred,  as  defects  in  the  casting,  sand-holes,  etc.,  are 
frequently  concealed  in  this  manner,  even  to  the  temporary  stand- 
ing of  gas  pressure,  but  in  the  long  run  such  stoppages  will  give 
way  and  leaks  occur. 

"  When  it  is  necessary  to  work  upon  a  broken  main,  etc.,  in 
frozen  ground,  it  is  convenient  to  thaw  the  ground  in  the  follow- 
ing manner:  A  recess  6  or  10  inches  deep  is  dug  over  the  section 
of  main  to  be  worked  on,  and  of  the  desired  length.  This  is  filled 
with  a  good  quality  of  unslaked  stone  lime  and  several  buckets 
of  water  thrown  thereon.  The  recess  is  then  covered  closely 
with  old  cement  sacks  and  boards  and  left  for  several  hours.  In 
this  manner  the  frost  can  be  drawn  from  the  ground  for  a  con- 
siderable depth. 

"  When  it  is  necessary  to  cross  a  bridge  with  a  gas-main,  the 
practice  should  be  to  run  from  the  lower  level  in  the  street  to 
the  upper  level  on  the  bridge  a  pipe  of  larger  diameter  than  the 
pipe  to  which  it  is  connected;  for  instance,  let  A  =  the  main  and 
F=the  risers  and  specials  crossing  the  bridge,  then  when  a  mam 
is  3  in.  it  requires  the  riser  to  be  6-in.  diam.;  for  A  4  in.,  B  must 
be  8  in.;  a  6-in.  main  requires  a  10-in.  riser;  an  8-in.  main  a  12-in. 
riser;  a  10-in.  main  a  14-in.  riser;  a  12-in.  main  a  16-in.  riser,  and  a 
16-in.  main  a  20-in.  riser.  Should  the  pipe  crossing  the  bridge 


148  AMERICAN  GAS-ENGINEERING  PRACTICE. 

be  exposed,  expansion  joints  should  be  placed  on  either  side  to 
take  up  vibration  and  change  of  temperature. 

"All  records  of  drips  and  valves  should  be  carefully  kept  not 
only  in  a  file  index,  but  also  entered  upon  the  company's  map, 
and  extensions  and  changes  corrected  thereon  and  kept  up  to 
date." 

The  following  paragraph,  taken  from  the  gas  educational 
trustees  of  the  American  Gaslight  Association,  cannot  be  too 
forcibly  urged  upon  the  attention  of  engineers  and  foremen: 

"In  the  laying  of  street  mains  it  is  of  the  utmost  importance 
to  see  that  all  pipes  are  on  a  slight  incline  or  gradient,  so  as  to 
drain  all  condensation  to  a  given  point  which  is  situated  at  the 
lowest  part  of  the  main,  where  all  the  condensation  is  collected 
by  means  of  drip-wells.  If  the  pipes  are  not  laid  on  a  perfect 
gradient  there  would  be  a  collection  of  water  in  the  various  parts 
of  the  pipes  where  sags  or  traps  occurred,  which  would  hinder 
and  stop  the  flow  of  gas  according  to  the  depth  of  the  trap  and 
the  amount  of  water  therein." 

For  all  sags  in  the  pipe-line,  drips,  or  traps,  proper  drip-pots, 
such  as  described  in  the  standard  specials  of  the  American  Gas- 
light Association,  should  be  provided. 

Cement  Pi pe= joints. — The  following  information  -upon  this 
subject  will  be  found  in  the  Proceedings  of  the  American  Gas- 
light Association: 

"The  cement  joint  for  street  mains  is  cheaper  than  the  lead 
joint.  It  is  more  rigid,  and  under  changes  of  temperature  is 
more  apt  to  remain  tight.  The  lead  joint  is  more  easily  cut  out 
than  the  cement  joint,  more  easily  repaired,  and  has  the  advan- 
tage of  ' coming'  and  'going'  with  the  changes  of  temperature, 
which,  in  the  case  of  the  cement  joint,  might  fracture  the  pipe." 
(See  Vol.  13,  p.  47.) 

"The  joints  commonly  employed  in  this  country  for  connect- 
ing together  the  separate  lengths  of  cast-iron  pipes  are  the  lead 
joint  and  the  cement  joint.  The  lead  joint,  while,  as  a  rule,  more 
expensive  than  the  cement  joint,  has  the  advantage  of  being 
more  easily  cut  out,  more  easily  repaired,  and  of  allowing  the 
pipes  to  expand  and  contract,  under  the  influence  of  changes  of 
temperature,  without  fracture,  since  the  lengths  can  move  in 
the  joints.  On  the  other  hand,  the  cement  joint  is  cheaper  and 
more  ri^id  than  the  lead  joint,  and  when  properly  made  will 
remain  tight  under  almost  any  possible  conditions.  A  line  of 
pipe  laid  with  cement  joints  if  exposed  to  changes  of  temperature 
will  not  show  small  leaks  at  the  joints  as  will  one  laid  with  lead 
joints,  but,  on  the  other  hand,  it  will  probably  be  fractured  in 
one  or  more  places.  In  most  instances  the  choice  between  lead 


MAINS.  149 

and  cement  joints  is  determined  by  the  relative  disadvantages 
of  a  number  of  small  leaks,  no  one  of  which  is  lar^e  enough  to  be 
dangerous,  and  one  large  leak,  which,  though  it  will  be  quickly 
detected,  may  cause  great  damage  before  it  can  be  repaired.  In 
one  large  city  lead  joints  are  used  in  the  heart  of  the  city,  where 
gas  from  a  large  leak  would  be  apt  to  accumulate  in  cellars,  sewers, 
and  electrical  conduits,  with  danger  of  disastrous  explosions,  and 
cement  joints  are  used  in  the  outskirts,  where  the  conditions 
are  favorable  for  the  gas  from  a  leak  passing  away  into  the  open 
air  without  forming  an  explosive  mixture  in  any  confined  spaces." 
(See  Vol.  17,  p.  137.) 

"Use  Portland  cement.  Natural  cements  are  not  uniform  in 
quality,  and,  as  a  rule,  are  too  quick-setting  to  permit  of  their 
use  with  safety.  In  selecting  the  brand,  take  a  relatively  quick- 
setting  Portland.  If  the  cement  sets  too  slowly  there  is  danger 
of  the  finished  joint  being  disturbed  before  setting.  Use  the 
cement  neat — no  sand.  Use  the  cement  as  dry  as  possible,  so 
that  it  requires  hammering  the  yarn  against  it  in  order  to  bring 
the  moisture  to  the  surface.  When  sufficient  water  is  added 
the  cement  will  still  appear  crumbly  in  the  pan,  and  will  just 
retain  the  impression  of  the  finrers  when  squeezed  in  the  hand. 
The  cement  should  be  used  immediately  after  mixing,  only 
enough  being  mixed  at  one  time  for,  say,  two  joints;  if  it  lies 
unused  over  five  minutes,  it  should  be  discarded.  The  cement 
remaining  in  the  pan  should  be  entirely  removed  before  mixing 


FIG.  30. — Cement  Joint. 

up  any  new  cement.  In  mixing  cement,  first  determine  the 
quantity  required  for  one  joint,  and  the  quantity  of  water  re- 
quired for  this  cement,  and  then  always  use  the  cement  and  water 
by  measurement.  Use  jute  yarn,  untarred.  When  the  joint  is 
made  the  yarn  and  sides  of  joint  may  be  moist  or  damp,  but 
should  not  be  wet  (Fig.  31).  The  finished  joint  should  con- 
sist of  one  roll  of  yarn  (A)  of  the  exact  circumference  of  the  pipe, 
twisted  and  driven  tightly  to  the  bottom  of  the  bell;  then  a 
solid  mass  of  cement  (£)  extending  to  a  point  about  1.5  in. 
back  of  the  face  of  the  bell;  then  a  second  roll  of  yarn  (C);  then 


150  AMERICAN  GAS-ENGINEERING  PRACTICE, 

a  facing  of  cement  (D).  Do  not  make  a  large  fillet  extending 
to  the  outside  diameter  of  bell.  In  entering  the  cement  be  very 
careful  to  completely  fill  the  whole  space.  A  wooden  pusher 
shaped  something  like  a  yarning-tool  is  useful  for  pushing  back 
the  cement  after  it  has  been  entered  by  the  hand.  Sometimes  a 
roll  of  yarn  is  used  to  drive  the  cement  back,  the  yarn  being 
withdrawn,  more  cement  entered,  and  the  process  repeated  until 
the  desired  quantity  has  been  entered.  After  the  first  yarn  is 
in,  and  before  the  joint  is  made,  the  pipe  should  be  thoroughly 
bedded  and  tamped  in  between  the  bell-holes,  to  prevent  any 
movement  of  the  joint  after  it  is  made.  When  the  joint  is  made, 
it  should  be  protected  from  the  sun.  As  few  joints  as  possible 
should  be  made  in  the  rain.  All  joints  should  be  tested  before 
being  covered  up.  The  test  is  made  by  connecting  gas  pressure 
to  the  new  pipe  through  a  meter,  thus  measuring  the  amount 
of  leakage,  if  any.  If  the  meter  indicates  leakage,  the  holes 
should  be  found  by  using  soap-suds  on  the  joints.  Fire  should 
never  be  used.  Better  still,  an  air-pump  and  mercury-gage 
may  be  employed.  The  joints  should  be  tested  only  after  the 
cement  has  set  sufficiently  to  prevent  its  being  hurt  by  the  soap- 
suds; where  feasible,  this  should  be  on  the  following  day. 

"In  the  sketch  (Fig.  31)  is  a  side  view  of  a  6-in.  cement  joint, 
with  part  of  the  hub  removed,  showing  cement  and  packing.  In 
the  sketch  C  is  the  cement,  P  packing.  After  the  pipe  has  been 
'sent  home '  graded,  and  the  joint  equalized  as  near  as  possible, 
1  in.  of  hemp  packing  is  firmly  driven  in  as  shown  in  the  pre- 


FIG.  31. — Another  Form  of  Cement  Joint. 

vious  illustration;  then  1  in.  of  cement  and  1  in.  more  of  pack- 
ing, followed  by  1J  in.  of  cement,  of  which  £  in.  is  on  the 
outside  of  hub,  and  slopes  from  center  of  rim  down  to  pipe  as 
shown.  To  make  this  joint  requires  3i  pounds  of  cement  and  sand 
mixed  dry — 2  parts  of  cement  to  1  of  sand — and  3  ounces  of  hemp 
packing.  The  joint  can  be  made  in  15  minutes." 

Lead  Pipe=joints. — "In  making  a  lead  joint  in  6-in.  cast-iron 
main,  the  first  step  in  the  operation,  after  the  spigot  end  of  one 
length  has  been  inserted  in  the  bell  of  the  other  and  the  length 
driven  home,  lined  up,  and  fixed  in  place  by  the  tamping  of  a 


MAINS.  151 

little  dirt  around  the  middle  of  it,  is  to  fill  solidly  with  packing 
a  portion  of  the  joint  space  between  the  spigot  and  bell,  the 
amount  of  space  so  filled  being  determined  by  the  depth  of  lead 
which  it  is  desired  to  have.  For  ordinary  straight  work  with 
6-in.  pipe  the  depth  of  lead  may  be  taken  at  1.5  in.,  and  the  joint 
space  will  therefore  be  filled  with  packing  to  a  point  1.5  in.  back 
from  the  face  of  the  bell.  Jute  packing,  either  plain  or  tarred, 
is  usually  employed.  Packing  which  has  been  allowed  to  absorb 
a  small  quantity  of  tar  can  be  driven  tighter  than  plain  pack- 
ing, but,  tar  being  cheaper  than  jute,  it  is  hard  to  avoid  the  pres- 
ence of  too  much  tar  in  tarred  packing,  and  for  this  reason  plain 
packing  is  often  given  the  preference.  A  sufficient  number  of 
strands  of  packing  should  be  twisted  to  form  a  rope  of  a  diam- 
eter a  trifle  larger  than  the  width  of  the  joint  space,  and  this 
should  be  cut  into  pieces  of  such  length  that  the  end  will  come 
into  close  contact  when  a  piece  is  placed  around  the  outside  of 
the  spigot  end  of  the  pipe  and  pulled  up  tight.  One  of  these 
pieces  is  used  to  lift  the  spigot  end  as  it  is  inserted  into  the  bell 
of  the  pipe  previously  laid,  and  is  sent  home  with  it,  thus  keep- 
ing the  spigot  central  in  the  bell  and  avoiding  the  necessity  of 
wedging  it  up  after  it  is  in  place.  This  piece  of  packing  is  driven 
solidly  into  place  in  the  bottom  of  the  joint  space  by  means  of 
a  calking-hammer  and  packing-iron,  and  other  pieces  are  in- 
serted one  at  a  time,  the  joint  in  each  ring  being  put  say  one- 
fourth  of  the  circumference  away  from  the  joint  in  the  pre- 
ceding ring,  and  each  driven  home,  a  sufficient  number  being 
used  to  fill  the  joint  space  to  the  required  depth,  leaving 
1.5  in.  for  the  lead.  The  packing  must  be  driven  hard  and 
the  finished  layer  must  be  of  uniform  depth,  so  that  the  lead 
space  will  be  uniform  all  around  the  pipe.  A  clay  roll  or  other 
form  of  joint  runner  is  then  placed  around  the  spigot  end  of  the 
pipe,  being  brought  tight  against  the  face  of  the  bell,  and  so  set 
as  to  leave  a  triangular  space,  having  its  base  on  the  pipe  and  its 
apex  on  the  face  of  the  bell  slightly  above  the  inside  edge,  which 
the  lead  can  fill  and  thus  make  it  certain  that  when  driven  the 
joint  will  be  of  the  shape  shown  in  the  cut.  Molten  lead  is  run 
into  the  joint  and  this  space  until  both  are  completely  filled  and 
the  lead  stands  above  the  highest  point  of  the  inside  edge  of  the 
bell,  the  lead  being  poured  in  through  an  opening  or  'gate  '  left 
on  top  of  the  pipe.  When  the  lead  has  hardened  the  joint  runner 
is  removed,  and  the  'gate '  or  lump  of  lead  where  the  opening 
for  pouring  was  made  is  cut  off.  The  lead  is  then  chiseled  all 
around  the  pipe  with  a  cold  chisel  and  calking-hammer.  This 
separates  the  lead  from  the  surface  of  the  pipe,  and  makes  a  groove 
in  which  the  first  calking-tool,  the  face  of  which  is  about  &  in. 


152 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


thick,  can  fit.  The  lead  is  driven  all  around  with  this  tool  and 
then  with  tools  successively  increasing  in  thickness  about  J  in. 
until  the  full  width  of  the  joint  has  been  reached.  The  work 
with  each  tool  should  be  begun  at  the  bottom  of  the  pipe  and 
carried  around  each  way,  finishing  up  at  the  top.  The  thickness 
of  the  last  tool  used  should  not  be  greater  than  the  width  of  the 
joint,  and  the  driving  with  this  tool  should  cut  the  lead  off  sharp 
with  the  inside  edge  of  the  bell,  otherwise  there  is  danger  that 
the  force  of  the  blows  will  be  expended  against  the  face  of  the 
bell  instead  of  doing  the  full  amount  of  work  that  it  should  do 
in  compressing  the  lead  in  the  joint.  -  In  order  to  have  the  tools 
fit  the  joints  exactly  it  is  well  to  have  them  made  in  sizes  vary- 
ing in  thickness  by  A  in.,  though  it  is  only  necessary  to  use  on 
any  joint  tools  varying  by  J  in.,  the  proper  sizes  being  selected. 
The  position  in  which  tools  are  naturally  held  when  calking  the 
joint  will  give  it  the  finished  shape  shown  in  the  cut,  if  the  joint 
runner  has  been  put  on  properly  and  sufficient  lead  used.  There 
will  be  required  for  making  a  6-in.  lead  joint  about  7  to  8  Ibs. 
of  lead  and  7  to  10  oz.  of  jute  packing.  A  good  workman  should 
be  able  to  average  nearly  3  joints  an  hour  for  a  day's 
work." 

TABLE  OF  CEMENT  AND  YARN   REQUIRED,  AS  PREPARED  BY 


Size  of 
Pipe. 

Cement  in  Quarts. 

Cement  in  Pounds. 

Water  in  Pints. 

Yarn  in 
Ounces. 

4" 

1    to  IJ 

2.25  to    4.10 

fteti 

4 

6" 

H  to  2 

4.10  to    5.50 

H  to  if 

6 

8" 

2    to  2$ 

5.50  to    6.87 

1|  to  li 

8 

10" 

2£to5 

6.87  to    8.25 

li  to  2 

10 

12" 

3    to  4 

8.25  to  11 

2    to2J 

12 

16" 

4    to  5 

11       to  13  f 

2J  to  2$ 

15 

20" 

5    to  6 

13J     to  16J 

2J  to  3£ 

20 

24" 

8    to  8£ 

20       to  23 

5    to5i 

27 

30" 

7    to?i 

19       to  21 

4    to  4* 

27 

Advantages  of  Various  Joints. — "  In  England  and  on  the  con- 
tinent of  Europe  a  great  variety  of  joints  for  cast-iron  pipe  have 
teen  devised  and  to  a  certain  extent  used.  These  include  mov- 
able flange  joints,  clip  joints,  collar  joints,  screwed  joints,  bell- 
and-sprrot  joints  in  which  the  joint  is  made  by  means  of  a  vul- 
canized rubber  ring,  and  bored  and  turned  joints  as  well  as  the 
fixed  flange  joints,  bell-and-spigot  joints  of  lead  or  cement,  and 
ball-and-socket  joints,  which  are  practically  the  only  joints  used  in 
this  country,  and  are  therefore  the  only  ones  considered  in  this 
article.  Flange  joints  allow  of  an  easy  removal,  when  desired, 


MAINS. 


153 


of  any  one  of  the  various  pieces  of  pipe.  They  are,  however, 
very  rigid,  and  their  use  is  confined  to  lines  of  pipe  above  ground 
and  at  the  works.  On  long,  straight  lines  of  flanged  pipe  one 
or  more  expansion  joints  should  be  provided  to  relieve  the  pipe 
of  the  strains  that  would  be  thrown  upon  it  by  its  expansion  and 
contraction  under  the  influence  of  changes  in  temperature.  Ball- 
and-socket  joints  are  expensive  and  are  used  only  for  lines  where 
great  flexibility  is  necessary,  as  in  laying  pipes  under  water. 


FIG.  32. — "  Cup-and-ball "  or  swivel  joint,  especially  used  in  crossing1  rivers, 
or  any  occasion  where  it  is  necessary  for  the  pipe  to  "  flex." 

Disjointing  Cement  Joints  may  be  most  easily  effected  by 
the  heating  of  the  pipe  bell  and  joint,  after  the  fashion  of  melting 
out  lead  joints. 

Cement  joints  should  never  be  made  in  pipe  recently  exposed  to 
the  sun,  without  first  reducing  the  temperature  of  the  pipe  to  that 
of  the  atmosphere  by  wet  cloths  or  water.  The  fresh  joint  should 
be  protected  from  the  heat  or  cold  by  shrouding  it  in  wet  or  dry 
burlap  or  bagging  respectively. 

In  cement  joints  untarred  yarn  is  to  be  preferred,  making  a 
more  homogeneous  joint. 

Combination  Joints. — A  frequent  practice  is  to  lay  the 
pipes  with  cement  joints,  except  at  intervals  of  from  six  to 
twelve  lengths,  where  a  lead  joint  would  be  put  in  to  act  as 


154  AMERICAN  GAS-ENGINEERING  PRACTICE. 

an  expansion  joint — the  location  being  marked  and  noted,  and 
the  lead  joint  occasionally  examined.  This  should  make  cement- 
jointed  pipe  practically  as  free  from  liability  to  fracture  as  lead- 
jointed  lines." 

The  whole  secret  of  success  in  joint-making  lies  in  the  yarn 
and  calking.  Every  yarn  joint  should  be  in  itself  perfectly 
gas-tight,  and  every  joint  yarned  or  finished  should  be  driven 
up  perfectly  tight  with  the  calking-tools.  The  first  requisite  of 
cement  joints  is  that  no  more  cement  should  ever  be  made  than 
is  to  be  used  within  five  minutes,  all  of  the  remaining  cement 
being  thrown  away  and  discarded,  as  after  that  time  the  setting 
has  begun  to  take  place. 

In  the  smaller  sizes  of  pipe,  where  it  is  inadvisable  to  use  a 
chisel  in  cutting,  roller  cutters,  such  as  the  Hall,  manufactured 
by  the  Walworth  Mfg.  Co.  and  the  Rodefeld  Mfg.  Co.,  may  be 
found  advantageous.  The  rollers  in  these  cutters  may  be  removed, 
retempered,  and  sharpened. 

It  should  be  remembered  as  the  basal  principle  of  all  cast- 
iron  pipe-joints,  whether  lead  or  cement,  that  the  first  yarn  driven 
should  be  of  itself  independently  "gas-tight."  If  this  work  is 
properly  executed,  the  yarn  being  tightly  calked  and  conscien- 
tiously worked  over,  the  material  subsequently  used  is  a  matter  of 
.secondary  importance. 

High=pressure  Pipe=joints. — In  laying  high-pressure  mains, 
which  should  be  of  extra  heavy  wrought-iron  or  steel  pipe,  where 
the  usual  coupling  is  used,  it  is  good  practice,  after  carefully  lubri- 
cating the  joints,  to  make  up  four  or  five  sections  of  pipe  hand- 
tight,  when  the  whole  may  be  screwed  up  with  a  power-winch. 
This  should  be  done  so  that  each  joint  is  turned  to  a  point  where 
the  threads  completely  disappear  within  the  socket  or  coupling, 
and  the  whole  will  be  found  not  only  a  most  effective  joint,  but 
capable  of  extraordinary  speed  in  execution,  thereby  greatly 
facilitating  and  expediting  the  labor  of  main-laying. 

For  the  taking  up  of  bends  in  the  pipe,  obviating  the  effects 
of  imperfectly  calked  joints,  and  to  reduce  the  electrolytic  damage 
of  current  jumping  around  the  joint,  a  pipe  has  been  designed, 
under  the  name  "  Universal,"  in  which  the  hub  and  spigot  ends 
are  machined  to  fit  tightly  without  any  packing  whatsoever.  The 
method  of  bolting  sections  together  by  flanges  and  a  section  of  the 
joint  are  shown  in  Fig.  33. 

Fig.  34  illustrates  not  only  how  to  allow  for  the  extra  length 
caused  by  the  joint,  but  also,  by  the  use  of  short  pieces  and  a 
nipple,  how  any  desired  length  may  be  obtained. 

For  ordinary  pressure  Universal  joints  should  not  be  drawn 
close  up.  When  ordering  pipe  for  exact  measurements  allow,  in 


MAINS. 


155 


addition  to  the  pipe  lengths,  for  each  male  end  as  specified  in 
the  table  below,  which  gives  the  average  exposure  of  the  joint 
when  made  up  as  represented  by  letter  A  in  Fig.  34. 


FIG.  33. — Universal  Joint. 


FIG.  34. — Universal  Joint  Connections. 

1,  the  hub  end  of  a  4-in.'pipe;  2,  4-in.  close  nipple:  3,  4-in.  elbow;  4,  4-in.  X2-ft.  pipe; 
5,  4-X9-in.  pipe;  6,  4-Xli-in.  space  nipple;  7,  4-in.  tee;  A,  i  in.,  which  is  the  exposed 
part  of  the  joint. 


Diam.  Pipe,         Averaged  Exposed  Portion  of  Joint 
Inches.  represented  by  A,  Inches. 

2 A 

3 A    . 

4 t 

5 i 

6 A 

8 * 

10 f 

12 f 

14 


The  following  are   some  of  the  usual  forms  of  high-pressure 
pipe-couplings: 


156 


AMERICAN  GAS-ENGINEERING   PRACTICE. 


Dresser  An^le-coupling. 


Insulating  Coupling,  Style  10,  for 
Special  or  Dresser  Style,  Cast-iron 
Pipe. 


Section  of  the  Dresser  Pipe-joint. 
A,  spigot;    B,  V-shaped  bell  of    pipe;    C, 
cement;  D,  malleable  iron  ring;  Fand  G,  bolt 
and  nut;  H,  asbestos  ring;  Rt  rubber  ring. 


Clamp  for  Matheson  Joints. 


Split  Sleeve  for  Repairing  Broken  Bell 
on  Cast-iron  Pipe. 


Clamp,  Style  4£,  for  Repairing  Leaks 
on  Regular  Hub  and  Spigot  Cast- 
iron  Pipe-head  or  Cement  Joints. 


Light  Split  Sleeve,  Style  13,  for  Repair- 
ing Wrought-iron  Pipe. 


Split  Sleeve,  Style  12,  for  Wrought- 
iron  Pipe.  Large  enough  to  go 
over  Dresser  Coupling  in  Case  of 
Accident. 


Insulating  Coupling  for  Dresser,  Style  9,    Split  Sleeve  for  Repairing  Broken 
Cast-iron  Pipe.  Cast-iron  Pipe. 

FIG,  35. 


MAINS.  157 

Although  high-pressure  service  merely  exaggerates  the  con- 
ditions of  low-pressure  transmission,  the  increased  duty  is  so  severe 
and  these  conditions  so  strongly  emphasized  as  to  make  necessary 
and  essential  a  perfection  of  engineering,  material,  and  workman- 
ship which  would  in  more  or  less  degree  be  otherwise  commercially 
dispensable. 

The  pipe  used  in  high-pressure  work  should  be  extra  heavy 
iron  or  steel,  and  of  the  best  quality  of  meter,  with  the  closest 
approximation  to  an  equality  of  texture  throughout,  free  from  chilled 
spots,  cores,  sand-holes,  etc. 

The  thr3ads  should  be  taper  and  constitute  the  best  order  of 
machine  work,  which  threads  in  the  transportation,  assembling, 
and  fitting  of  the  pipe  should  receive  infinite  care,  to  prevent  bruis- 
ing, chamfering,  or  stripping.  These  threads  should  be  carefully 
examined  by  a  competent  inspector  immediately  before  "  making - 
up,"  all  pipe  with  defective  threads  being  discarded,  their  threaded 
section  being  cut  off  and  the  threads  re-run.  Although  this  may 
seem  an  extravagance,  it  is  in  reality  economical  practice,  and 
should  be  adhered  to  without  deviation. 

'The  quality  of  valves,  cocks,  fittings,  etc.,  is  also  most  important. 

Commercially  speaking  and  to  all  practical  purposes,  the  quality 
of  brass  varies  between  two  extremes,  its  highest  refinement 
and  efficiency  being  reached  at  an  approximate  composition  of  red 
brass  consisting  of  90  parts  copper,  10  parts  tin,  and  2  parts  zinc, 
while  at  the  other  or  opposite  extreme  we  find  a  yellow  brass  as 
low  as  in  copper,  as  50  parts  copper  and  50  parts  zinc.  The  various 
grades  and  qualities  of  brass,  commercially  used  and  for  the  manu- 
facture of  fittiir  s,  lie  between  these  extremes,  although  the  former 
is  occasionally  and  the  latter  frequently  reached. 

Red  brass  of  the  composition  named  attains  a  tensile  strength 
of  68,000  Ibs.  per  square  inch,  while  the  yellow  alloy  runs  as  low  as 
10,000  Ibs.  per  square  inch  tensile  strength,  the  various  compositions 
and  formula  now  in  commercial  service  varying  between  these 
extremes  very  exactly  in  ratio  with  the  preponderance  of  copper 
and  the  amount  of  tin  and  zinc. 

As  the  proportion  of  lead,  zinc,  and  tin  becomes  higher  and  the 
preponderance  of  copper  less  in  the  mixture  obtained  each  ingre- 
dient preserves  more  distinctly  its  individual  characteristics  and 
attributes. 

Going  from  red  to  yellow  brass,  the  tendency  is  to  revert  from 
the  close-prained  tenacious  copper  to  the  spongy  zinc.  In  alloying 
elements  of  such  widely  varying  gravities  as  copper,  lead,  and  tin, 
when  such  elements  are  in  a  molten  state  some  separation  or  segre- 
gation must  take  place,  the  heavier  metals  going  to  the  bottom  of 
the  molten  mass  in  the  order  of  their  respective  weights.  It  is 


158  AMERICAN  GAS-ENGINEERING  PRACTICE. 

necessary  to  overcome  this  tendency  by  a  certain  amount  of  agita- 
tion ;  if  this  is  incomplete,  the  result  is  an  unequal  distribution  of  the 
elements  throughout  the  admixture.  This  condition  tends  to 
destroy  any  possible  homogeneity  in  the  structure  and  fiber  of  the 
resultant  casting,  and  such  inequality  in  the  metal  causes  rapid 
excoriation,  unequal  grinding,  as  well  as  scoring  of  working  parts 
and  bearings  where  they  meet. 

If  we  take  two  fittings,  one  a  red  and  another  of  the  yellow 
metal,  and  place  them  on  an  anvil,  striking  them  in  succession  with 
a  sledge-hammer,  using  the  same  degree  of  force,  it  will  be  observed 
that  while  the  red-brass  casting  may  become  slightly  distorted,  the 
brittle  yellow-brass  casting  will  fly  in  pieces.  This  is  due  to  the 
extreme  tenacity,  ductility,  and  elasticity  of  the  red  brass  obtained 
from  its  copper  component,  a  peculiarity  which  the  writer  has 
observed  in  fittings  during  experiments  with  the  Barrett  pipe- 
forcing  jack.  In  a  number  of  instances  where  obstructions  were 
encountered,  under  the  enormous  amount  of  pressure  from  the 
jack,  the  fitting  was  completely  distorted  without  breaking,  but, 
even  in  its  distorted  condition,  preserved  its  tightness  against 
leaking.  Moreover,  it  was  found  even  in  the  case  of  the  standard- 
weight  fitting  that  the  pipe  in  the  connection  ruptured  under  the 
stress  before  the  fitting  would  give  way. 

Another  illustration  of  the  extreme  tenacity  of  the  red  brass  is 
shown  by  the  fact  that  it  is  nearly  50  per  cent,  more  difficult  to 
machine,  polish,  and  buff  than  is  yellow  casting,  being  prima  facie 
proof  that  a  metal  which  will  resist  the  incursion  of  the  machine 
tool  will  possess  paramount  qualities  from  a  wearing  standpoint, 
and  possesses  the  highest  resistance  to  all  forms  of  erosion. 

While  copper  is  not  ordinarily  affected  or  corroded  by  such 
agencies  as  moisture  or  acids  inducing  rust  and  oxidation,  yet  tin, 
zinc,  and  lead  are  especially  affected  by  these,  and  we  may  there- 
fore say  that  fittings  are  susceptible  to  rust,  oxidation,  or  corrosion 
in  direct  ratio  with  the  amount  of  tin,  zinc,  and  lead  which  they 
contain. 

Inasmuch  as  corrosion  attacks  that  portion  of  any  structure 
which  is  most  delicate,  its  inroads  principally  affect  the  threads  and 
working  surface  of  these  fittings,  and  leaks  are  more  often  occa- 
sioned by  this  agency  than  are  usually  conceded. 

Especial  attention  is  here  called  to  the  fact  that  in  testing  a  fit- 
ting for  high-pressure  gas  or  air,  the  hydraulic  test  is  only  good  as 
indicating  the  tensile  strength  of  the  fitting  and  not  to  indicate 
tightness,  it  being  found  that  valves  or  cocks  found  tight  under 
the  300  Ibs.  of  water  pressure  frequently  leak  when  subjected  to 
40  Ibs.  of  air.  This  fact  seems  little  known  among  either  manu- 
facturers or  engineers,  but  it  will  be  found,  as  a  rule,  that  when  a 


MAINS. 


159 


fitting  is  found  tight  under  a  pressure  of  40  Ibs.  it  will  be  tight 
under  any  other  reasonable  pressure,  or,  generally  speaking,  up  to 
its  safe  working  capacity  or  even  to  the  rupture  point  of  the  metal. 
Globe=valves,  Tees,  and  Elbows. — The  reduction  of  pressure 
produced  by  globe-valves  is  the  same  as  that  caused  by  the  follow- 
ing additional  lengths  of  straight  pipe,  as  calculated  by  the  formula: 


Additional  length  of  pipe= 


1 14  X  diameter  of  pipe 
1  + (3.6 -diameter)    ' 


Diameter  of  pipe, 
Additional  length 

Diameter  of  pipe 
Additional  length 


112 

4     7 


10 


3 

13 


3J    4 
16     20 


5 

28 


6  inches 
36  feet 


.7     8   10    12      15     18     20     22     24  inches 
44  53   70   88   115   143   162   181   200  feet 


The  reduction  of  pressure  produced  by  elbows  and  tees  is  equal 
to  two-thirds  of  that  caused  by  globe-valves.  The  following  are 
the  additional  lengths  of  straight  pipe  to  be  taken  into  account 
for  elbows  and  tees.  For  globe- valves  multiply  by  f : 


Diameter  of  pipe, 
Additional  length 

Diameter  of  pipe. 
Additional  length, 


1  1J  2     2j  3  3J     4       5       6  inches 

.2  3     5     7  9  11      13     19  24  feet 

7  8   10  12  15  18     20     22  24  inches 

30  35  47  59  77  96  108   120  134  feet 


These  additional  lengths  of  pipe  for  globe-valves,  elbows,  and 
tees  must  be  added  in  each  case  to  the  actual  length  of  straight 
pipe.  Thus  a  6-inch  pipe  500  feet  long,  with  1  globe-valve,  2  elbows, 
and  3  tees,  would  be  equivalent  to  a  straight  pipe  500  +  36  +  (2  X24) 
+  (3X24)  =  656  feet  long. 

Joints  for  High=pressure  Mains. — All  sockets  or  couplings 
shall  be  extra  heavy,  of  the  best  quality  of  metal,  and  have  taper 
threads.  Preferably  these  joints  should  be  tight  and  free  from 
leakage  without  the  use  of  "dope,"  but  where  some  joint  com- 
pound is  necessary  litharge  and  glycerine  are  best  used. 

Where  flange-joints  of  any  kind  are  used,  the  gasket  should  be 
made  of  ^-in.  lead  wire,  the  ends  of  which  are  soldered  together. 

Where  valves  are  used  upon  high-pressure  lines  or  storage- 
tanks  instead  of  cocks,  these  too  should  be  of  the  extra-heavy 
ammonia  type,  although  even  these  will  be  found  to  give  more  or 
less  trouble,  unless  of  a  first-class  quality  and  carefully  selected. 

Main=regulators. — Where  high-pressure  mains  are  controlled 
through  automatic  regulators  the  equipment  should  invariably 
be  in  duplicate,  the  regulators  being  connected  into  the  line  in 


160  AMERICAN  GAS-ENGINEERING  PRACTICE 

parallel,  and  each  equal  to  sustaining  the  maximum  load  of  the 
entire  line.  The  regulators  should  be  connected  in  with  proper 
valves  and  possess  by-passes  between  their  inlets  and  outlets,  all 
of  which  connections  to  be  flanged,  to  expedite  ready  removal 
and  replacement.  All  of  the  above  should  be  surrounded  by  proper 
brick  or  concrete  manholes  to  afford  accessibility. 

Drips. — All  traps,  pockets,  or  depressions  in  almost  every  high- 
pressure  fine  should  be  dripped  after  the  method  of  low-pressure 
practice.  This  may  usually  be  done  by  cutting  into  the  line  a  tee 
(looking  down  and  whose  opening  is  equal  to  the  diameter  of  the 
pipe)  into  whose  run  a  short  section  of  pipe  is  connected,  which  is 
duly  capped  and  fitted  with  a  small  relief -pipe  terminating  at  some 
convenient  place  and  fitted  with  a  pocket-head  pet-cock,  which 
latter  acts  as  a  "  bleeder."  Through  an  arrangement  of  this  kind 
the  condensation  accumulating  in  the  drip  can  be  periodically 
"blown  off."  This  condensation  is  usually  created  by  the  change 
of  vapor  tension  due  to  the  varying  compression  upon  the  vol- 
ume of  gas  in  the  main,  extending  from  the  maximum  pressure 
during  peak  load  hours  to  possibly  atmosphere  or  merely  holder 
pressure  (if  the  service  be  a  booster  or  feeder  line) ,  or  at  least  con- 
siderably reduced  during  the  period  of  minimum  demand. 

Anchorage. — All  bends  and  curves  in  high-pressure  mains 
should  be  firmly  anchored  in  order  to  prevent  gyration ;  the  straight 
runs  should  also  be  heavily  anchored,  perhaps  about  twice  as  often 
as  the  expansion  joints  (about  one  every  500  ft.).  Expansion 
joints  and  lateral  branches  of  all  sorts  should  also  be  strongly 
anchored  to  prevent  buckling  and  thrust.  The  tendency  of  a 
high-pressure  main  to  "  writhe  "  is  much  greater  than  is  generally 
known,  for,  in  addition  to  the  initial  pulsations  caused  by  the 
compressor,  there  is  a  reflex  which  creates  a  powerful  " gas-hammer." 

Expansion  Joints  should  be  placed  not  less  frequently  than 
one  every  1000  feet. 

Testing  High=pressure  Mains  is  done  much  after  the  fashion 
of  low-pressure  work,  with  the  exception  that  a  portable  air-com- 
pressor, say  6  H.P.,  direct-connected  to  a  gasoline-,  alcohol-,  or 
vapor-engine,  is  generally  used.  An  outfit  of  this  kind  will  also  be 
found  extremely  convenient  for  a  number  of  purposes;  it  can  have 
in  its  equipment  a  centrifugal  pump  and  hose  connections,  which 
will  be  found  of  great  convenience  in  emptying  ditches,  cesspools, 
drips,  etc.,  of  water,  with  a  saving  of  time  and  labor. 

Pneumatic  Tools. — The  compressor  may  also  be  fitted  with  a 
pneumatic  hammer  into  which  cape  and  diamond-point  chisels 
may  be  used  for  cutting  pipe;  and  with  calking-tools  for  driving 
up  joints.  These  tools  should  fit  the  chuck  loosely  so  as  to  move 
freely  in  the  workman's  hand.  The  calking  done  by  the  pneu- 


MAINS. 


161 


matic  hammer  is  far  superior  to  that  done  by  hand,  being  equal 
throughout,  and  especially  driving  home  the  lead  at  the  bottom 
of  the  joint  and  underneath  the  pipe,  which  is  usually  slighted 
in  handwork.  It  has  the  further  advantage  of  time  and  economy, 
and  in  permitting  the  ordinary  laborer  to  do  a  better  job  of  calking 


ALCOHOL 

.t  Benzine  ran*. 

FIG.  36 — Naphthalene  Removal  Vaporizer. 

than  that  usually  accomplished  by  a  skilled  and  expensive  work- 
man. 

Pipe  Deposits. — To  remove  stoppages  in  the  mains,  services, 
meters,  house-pipes,  fixtures,  and  burners,  and  to  clear  out  naph- 
thalene, tar,  and  other  hard  stoppages,  the  writer  has  found  it 


162 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


convenient  to  vaporize  wood-alcohol  or  benzine  and  inject  it 
into  the  mains  by  means  of  a  vaporizer  (Fig.  36),  a  diagram  of 
which  is  herewith  given. 

A  quantity,  say  20  gallons,  of  alcohol  is  put  into  a  tank  and 
admitted  through  a  sight-feed  into  a  drum,  where  it  is  vaporized 
by  a  steam-coil.  The  inlet  of  this  drum  is  duly  sealed  by  a  pipe- 
trap  in  order  to  prevent  the  return  of  the  vapor  or  the  exit  of 
the  gas  into  the  alcohol-tank.  This  alcohol  vapor,  passing  out 
through  another  trap,  is  admitted  into  the  mains  and  carried  for- 
ward by  the  gas,  experiment  showing  it  to  have  a  travel  of  at 
least  3  miles.  It  instantly  dissolves  all  naphthalene  and  invari- 
ably attacks  and  makes  soluble  other  similar  substances.  Ten  or 
15  gallons  per  1,000,000  cu.  ft.  thus  admitted  into  the  mains  for  a 
day  or  so,  say  twice  a  year,  will  be  of  incalculable  value  in  cleansing 
the  system,  especially  where  Welsbach  service  is  extensively  used. 

Leaks. — The  question  of  leakage,  or  a  large  portion  of  what 
is  known  as  "gas  unaccounted  for,"  should  be  a  matter  of  con- 


roftG6t>  -ROUND 


T 


BAA  f OR    LOCATING 


FIG.  37. — Pavement-piercing  Bar. 

stant  attention  upon  the  part  of  the  superintendent.  Of  course 
a  large  portion  of  this  seeming  discrepancy  is  by  reason  of  change 
of  temperature,  either  during  the  process  of  works  distribution  or 
after  storage,  gas  varying  -^-%  of  its  bulk  approximately  for  every 
degree  Fahrenheit  over  32°  above  zero.  There  is,  however,  in 
all  systems  a  certain  amount  of  leakage  due  to  bad  joints,  which 
occur  either  from  poor  construction,  change  in  temperature,  or 
instability  on  the  part  of  the  ground  or  foundation  where  laid. 
The  entire  system  of  every  gas  company  should  be  periodically 


MAINS.  163 

"barred."  An  iron  bar  (Fig.  37)  with  a  loose  handle  for  removing, 
large  at  one  end  to  form  an  anvil  for  the  sledge  and  tapering  at 
tha  other,  should  be  driven  down  at  the  bell  end  of  a  pipe,  such 
joint  being  first  definitely  located.  Great  care  should  be  taken 
that  the  bar  should  not  be  driven  with  sufficient  force  to  injure 
the  pipe,  and  to  this  end  it  is  better  to  use  a  bar  with  a  malleable 
point  than  a  steel  bar,  which  is  apt  to  cut.  The  bar  then  being 
removed  from  contact  with  the  bell,  leaking  gas  should  be  sought 
in  the  hole  thus  made,  first  by  the  sense  of  smell  and  afterwards 
by  the  application  of  a  match. 

Test  for  Leakage. — Under  conditions  where,  by  reason  of  a 
comparatively  odorless  gas  or  for  other  reasons,  it  is  impracticable  to 
discover  leakage  by  the  sense  of  smell,  test  may  be  made  by  applying 
at  suspected  points  a  paper  saturated  with  a  solution  of  palladous 
chloride  from  which  metallic  palladium  is  precipitated  in  the  pres- 
ence of  traces  of  carbon  monoxide;  the  reaction  being  as  follows: 

PdCl2+CO+H2O=Pd+2HCl+CO2. 

The  blackening  of  the  paper  indicates  the  presence  of  CO  gas. 

Records. — A  measurement  should  then  be  taken  in  the  direc- 
tion of  the  run  of  the  pipe  (equal  to  one  length  of  the  pipe)  and 
the  next  joint  located,  when  the  experiment  can  be  repeated. 
All  leaks  discovered*  should  be  marked,  reported,  dug  up,  and  re- 
calked.  Where  the  calking  lead  drives  up  too  far,  a  new  lead 
joint  should  be  run  and  its  tightness  ascertained  by  the  applica- 
tion of  heavy  soap-suds. 

This  sort  of  work,  together  with  all  repair  work,  can  be  greatly 
facilitated  by  the  use  of  accurate  records  in  the  office,  recording 
the  location  of  all  pipes,  drips,  valves,  services,  etc.,  indicating 
the  direction  of  flow,  the  juncture  of  feed-line  and  crosses,  etc. 
In  order  to  bring  this  information  to  the  office,  where  a  proper 
record  can  be  made  and  filed,  the  writer  suggests  the  use  of  a 
card  (Fig.  38),  which  should  be  supplied  to  the  foreman  of  main 
construction,  who  can  fill  in  thereon,  with  a  rule  and  pencil,  the 
location  of  pipe,  distance  from  property  line,  class  of  fittings, 
location  of  valves,  drips,  crosses,  etc.,  and  the  direction  of  fall. 
From  these  cards  a  map  can  be  made,  showing  an  entire  district, 
which  will  be  found  valuable  in  the  regulation  of  pressure  and 
the  addition  of  extensions,  after  which  the  card  should  be  filed 
for  future  use. 

Service  Connections.  —  It  is  doubtful  whether  under  any 
conditions  it  is  good  economy  to  use  galvanized  pipe  for  ser- 
vices, inasmuch  as  nearly  all  agencies  which  tend  to  destroy  black 
iron  will  also  attack  the  zinc  coating  of  galvanized  pipe.  Medium- 
weight  steel  pipe  will  be  found  far  better. 


164 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


It  is  good  practice  in  connecting  a  service  with  the  main  to 
tap  the  latter  on  top  and  screw  therein  a  street  T.  The  street  L 
is  then  screwed  into  the  street  T  at  its  side  outlet,  thereby  form- 
ing a  swing  joint.  The  chief  advantage  of  this  connection  is  that 
gas  can  be  cut  off  by  the  opening  in  the  T  from  the  service  while 
it  is  being  laid,  which  opening  can  be  also  used  for  examining  the 


IJ 

M 

il 


DISTANCE  TO  PROPERTY  LINE 


DISTANCE  TO  PROPERTY  LINE 


DEPTH 


<  DEPTH        —STREET 


DISTANCE  TO  PROPERTY  LINE 


DISTANCE  TO  PROPERTY  LINE 

i 

CO 

s 

§ 

=• 
»- 

1 

s 

§ 

E 

$ 

g 

j 

f 

E 

< 

E 

DISTANCE  TO  PROPE 

ENGTH  OF  BLOCK 

NOICATES  POINT  TWENT 
OPERTY  CORNER. 

rE  DIRECTION  OF  FALL. 

OCATION  OF  ALL  VALVES 

re  POSITION  AND  SIZE  O 

;LASS  OF  PIPE,  SIZE  OF 

-1 

i£ 

0 

* 

5 

B 

E 

| 

i 

1 

i                         __ 

FIG.  38. — Main  and  Service  Chart. 

service  in  case  of  trouble.     It  also  relieves  both  pipes  from  either 
horizontal  or  vertical  strain  in  settling  or  crawling   (Fig.  39). 

There  are  two  methods  of  cutting  cast-iron  pipe,  both  of  which 
can  be  recommended.  The  more  convenient,  especially  for  sizes 
under  12  in.,  is  the  Hall  cutter,  which  can  be  used  after  the  man- 


MAINS. 


165 


ner  of  wrought-iron  pipe-cutters;  otherwise  the  pipe  should  be 
cut  around  with  a  diamond-nosed  chisel  until  a  ring  at  least  ^  in. 
deep  has  been  formed,  when  the  pipe  may  be  severed  with  the 
aid  of  a  dog-chisel. 

In  pipes   over  bridges,   contraction   and   expansion,   together 
with  vibration,  must  be  allowed  for.     Wrought-iron  pipe  is  gen- 


t  (rift re  mm 


FIG.  39. — Plug  for  T  Connection  to  Prevent  Gas  Escaping  while  Laying 

Service  Irises. 

erally  used  in  preference  to  cast,  and  at  either  end  expansion  joints, 
or,  better  still,  the  Dresser  sleeves,  are  placed.  There  should  be 
valves  on  either  side  of  the  bridge  to  control  the  flow  of  gas  in 
case  of  accident.  These  pipes  should  be  kept  thoroughly  coated, 
inasmuch  as  the  sulphur  in  engine  smoke,  in  the  case  of  railway 
bridres,  is  most  deleterious  in  its  action. 

It  is  the  custom  of  a  number  of  companies  in  the  United  States 
to  base  their  extension  of  mains  into  unoccupied  territory  upon 
one  prospective  consumer  to  every  100  feet  of  main.  The  ad- 
vantage of  this  system  seems  to  be  demonstrated  by  the  best 
practice. 

All  valves  in  a  main  system  should  systematically  and  con- 


166  AMERICAN  GAS-ENGINEERING  PRACTICE. 

sistently  be  either  all  right-handed  or  all  left-handed,  that  is, 
closing  in  the  direction  of  the  hands  of  a  clock  or  the  reverse. 
This,  more  than  anything  else,  prevents  confusion  and  the  pos- 
sibility of  having  a  valve  in  the  system  closed  without  the  likeli- 
hood of  discovery. 

One  of  the  great  nuisances  in  gas  distribution  is  the  formation 
of  iron  carbonyl.  It  may  possibly  be  the  result  of  unoxidized 
purifying  material,  but  is  more  likely  the  result  of  gas  coming 
in  contact  with  new  iron  borings,  such  as  the  tapping  of  a  large 
number  of  services  into  a  new  section  of  main  is  apt  to  produce. 
It  appears  generally  at  the  burner  tip  and  may  be  remedied  by 
the  admission  of  water  into  either  main,  services,  or  purifying- 
boxes  to  complete  the  oxidation. 

The  general  advantages  of  cast-iron  over  wrought-iron  pipe 
for  gas  purposes  are:  first,  its  greater  ability  to  resist  the  cor- 
rosion of  the  soil;  secondly,  its  greater  thickness  between  internal 
and  external  diameters,  permitting  better  service  connection  and 
abolishing  the  necessity  of  additional  fittings  for  such  connec- 
tions, thereby  reducing  the  liability  to  leakage. 

Repairing  Breaks.  —  In  case  of  broken  mains  a  temporary 
repair  can  be  made  by  bandaging  with  cloth  between  the  folds 
of  which  are  wrapped  copious  layers  of  soap,  pipe-clay,  or,  better 
still,  Tucker's  cement,  portions  of  which  filling  having  been  pre- 
viously forced  into  the  crack  or  crevice  of  the  pipe  before  the 
application  of  the  bandage.  The  permanent  remedy  depends 
upon  the  nature  of  the  injury.  Should  the  break  run  around 
the  circumference  and  the  entire  damage  be  included  within  a 
lateral  space  of  4  or  5  in.,  a  split  sleeve  may  be  used.  Should, 
however,  the  break  run  lengthwise  the  pipe,  the  better  practice 
is  to  cut  out  the  injured  section,  replacing  it  with  new  pipe,  the 
final  joint  being  made  with  a  solid  sleeve  which  is  slipped  over 
the  joint. 

When  a  split  sleeve  is  used,  the  pipe  must  be  first  thoroughly 
cleaned  of  all  dirt  and  rust,  and  if  it  is  settled  it  should  be  blocked 
back  into  proper  grade  and  alignment.  A  strip  of  unbleached 
muslin,  wide  enough  to  cover  the  break,  with  a  margin  of  6  or 
8  in.  on  either  side,  and  long  enough  to  circle  the  pipe  twice  or 
more,  should  be  smeared  thickly  with  putty  or  Tucker's  cement, 
or  a  mixture  of  equal  parts  of  white  and  red  lead  and  linseed-oil, 
and  wrapped  tightly  around  the  pipe  above  the  break. 

A  split  sleeve  can  then  be  applied  so  as  to  cover  the  break, 
with  a  margin  of  at  least  4  in.  on  either  side.  The  joint  between 
the  sleeve  and  the  pipe  may  be  made  as  follows:  A  number  of 
pieces  of  millboard  soaked  to  a  pulp  in  hot  water  may  be  forced 
between  the  sleeve  and  the  pipe  and  tightly  corked.  When  this 


MAINS. 


167 


is  dry  a  lead  or  cement  joint  of  the  regular  .type,  the  former  pre- 
ferred, may  be  made  on  either  end  of  the  sleeve. 

When  it  is  necessary  to  remove  altogether  a  damaged  section 
of  pipe,  the  pipe  should  be  cut  at  a  distance  not  less  than  8  in. 


FIG.  40.— Method  of  "  Cutting"  in  a  Fitting  (Correct),  Using  a  Solid  Sleeve. 


FIG.  41. — Method  of  "Springing"  in  a  Fitting  (to  be  Avoided)  without  Use  of 

Sleeve. 

prior  to  appearance  of  the  break  or  crack;  this  cut  may  be  made 
either  by  the  use  of  regular  pipe-cutters,  or  by  cutting  around 
with  a  diamond-nosed  chisel  and  severing  with  a  dog-chisel. 
When  the  new  section  is  installed,  aligned,  and  graded  before 
sliding  the  sleeve,  which  in  this  case  should  be  solid,  into  place, 
the  spigot  ends,  which  must  just  meet,  should  be  brought  to- 
gether and  wrapped  with  unbleached  muslin,  prepared  as  before 
described,  with  the  use  of  the  split  sleeve.  The  solid  sleeve  may 
then  be  slid  over  the  bandage  and  the  joint  made  as  before  de- 
scribed in  the  regular  manner. 

Flour  or  meal  in  small  sacks  has  on  several  occasions  been 
used  to  choke  dangerous  fires  occurring  through  leakage  in  man- 
holes. 

Main=stoppers. — In  bagging  off  a  main  that  is  likely  to  be 
internally  coated  with  naphthalene  or  rust,  the  rubber  ba«;  should 
be  inserted  in  a  canvas  cover  in  order  to  protect  the  rubber  sur- 
face from  the  action  of  the  oily  deposit.  This  may  be  placed 
by  use  of  a  bag  fork,  which  is  a  simple  wire  contrivance,  with 
blunt  end.  Where  the  main  is  under  considerable  pressure,  it 
should  be  doubly  bagged,  two  separate  taps  and  bags  being  placed 
on  each  gas-head,  and'  as  an  additional  precaution,  where  the 
pressure  is  especially  hrrh,  a  patent  gas  diaphragm  stopper,  con- 
sisting of  a  contrivance  of  canvas  and  wires,  may  be  placed  before 
the  bag  in  a  separate  tap.  It  is  well  to  use  bags  one  size  larger 


168  AMERICAN  GAS-ENGINEERING  PRACTICE. 

than  the  diameter  of  the  tap  to  be  plugged.  These  bags  should 
always  be  inflated  by  the  use  of  a  small  hand  bicycle  pump,  and 
never  by  the  lungs,  as  the  breath  condensation  is  deleterious  to 
the  rubber,  to  say  nothing  of  the  effect  upon  the  workmen  of 
the  gas  inhaled. 

Gas  bags  after  use  may  be  preserved  by  being  inflated  with 
dry  air,  the  necks  being  corked,  instead  of  tied,  with  wooden  pins 
or  plugs.  The  bags  should  then  be  coated  with  tallow  and  stored 
in  a  damp  place. 

Successful  efforts  have  been  made  to  bag  off  a  main  with 
water,  extra-strong  bags  being  used. 

Repair  Work. — Pressure  may  be  shut  off  and  the  end  of  a 
main  plugged  temporarily  by  the  use  of  a  large  compact  ball  of 
cloth  or  cord,  fitting  the  pipe,  to  which  proper  straps  have  been 
firmly  attached  to  facilitate  ready  removal. 

COSTS  OF  INSTALLING  MAINS. 

Excavation  Costs. — The  following  table,  for  which  the  writer 
is  indebted  to  M.  E.  Malone,  will  be  of  value  in  estimating  labor 
operations,  and  constitutes  a  very  fair  average  of  work  in  hand- 
ling different  kinds  of  material  that  the  average  laborer  can  handle 
in  a  specified  time,  in  cu.  ft.  per  man  per  hour. 

MATERIAL   HANDLED    PER   MAN. 

Cu.  Ft. 
per  Man-hour. 

Asphalt  (3.5-in.  and  6-in.  concrete) 4.298 

Sand  and  clay 24.700 

Clay " 19.220 

Sand  and  broken  stone 22.000 

Loam 35.000 

Broken  shale 17.330 

Cost  of  Loading  and  Hauling  Cast=iron  Pipe. — Much  of  t*he 
following  data  is  from  Gillette's  Handbook  of  Cost  Data.  Three 
men  assisted  by  a  driver  averaged  5'  lengths  of  12-in.  pipe  loaded 
from  a  flat  car  to  a  wagon  and  the  pipe  was  rolled  down  the  plank 
runway.  This  same  gang  would  unload  a  wagon  in  6  minutes. 
As  each  length  of  pipe  weighed  nearly  £  short  ton,  the  wagon 
load  was  2.5  tons.  It  therefore  cost  5  cents  per  ton  to  load  and 
2.5  cents  per  ton  to  unload  the  wagons,  wages  of  men  being  15  cents 
per  hour;  but  this  does  not  include  the  lost  time  of  two  horses 
during  loading  and  unloading,  which  is  equivalent  to  about  2  cents 
per  ton.  The  total  fixed  cost  of  loading;  and  unloading  was  10  cents 
per  ton,  including  team  time.  The  hauling  costs  12  cents  per 


MAINS.  169 

ton  per  mile  where  2.5  tons  are  the  load  (wages  of  team  and 
driver  35  cents  per  hour)  and  the  team  returns  empty.  Good 
hard  level  roads  are  required  for  so  large  a  load.  If  the  haul 
is  short  and  this  loading  gang  of  3  men  walks  along  with  the 
wagon,  the  cost  of  hauling  becomes  25  cents  per  ton-mile  in- 
stead of  10  cents. 

Pipe  should  never  be  shipped  in  hopper-bottom  cars,  for  the 
difficulty  of  unloading  adds  very  much  to  the  cost.  I  have  had 
a  gang  of  6  men  who  unloaded  only  75  lengths  of  12-in.  pipe  in 
10  hours  from  a  hopper  gondola  into  wagons.  Each  length 
weighed  800  Ibs.,  making  30  tons  the  day's  work  at  30  cents  per 
ton.  This  work  was  by  hand,  no  derrick  being  available. 

Trenches  for  water-pipes  in  the  northern  United  States 
are  usually  5  ft.  deep  from  the  surface  of  the  street  to  the  axis 
of  the  pipe.  In  the  South  trenches  are  only  3  ft.  deep.  Water- 
pipe  trenches  are  usually  dug  not  less  than  18  to  24  ins.  wider 
than  the  inside  diameter  of  the  pipe;  and  just  before  the  pipes 
are  laid  a  gang  of  men  enlarge  and  deepen  the  trench  for  a  short 
space  where  each  pipe  joint  is  to  come;  this  is  called  digging 
the  " bell-holes."  The  bell-holes  enable  the  yarners  and  calkers 
to  make  the  joints  properly.  It  is  usually  not  necessary  to 
brace  the  sides  of  a  trench  that  is  only  5  or  6  ft.  deep. 

Cost  of  Trenching. — At  Corning,  N.  Y.,  a  trench  for  a  10-in. 
water-pipe  was  excavated  2.5  ft.  wide  X  5  ft.  deep  X  1500  ft. 
long,  which  equals  600  cu.  yds.,  in  4.5  days  by  24  men,  or  at  the 
rate  of  6  cu.  yds.  per  man  per  10-hour  day,  equivalent  to  1 1  cents 
per  running  foot  or  25  cents  per  cu.  yd.  The  backfilling  was 
done  in  three  days  by  2  men  and  1  horse  with  driver,  usin°;  a 
drag  scraper  and  a  short  length  of  rope,  so  that  the  horse  worked 
on  one  side  of  the  trench  while  the  two  men  handled  the  scraper 
on  the  opposite  side,  pulling  the  scraper  directly  across  the  pile 
of  earth.  In  this  way  the  backfilling  was  made  at  a  cost  of  1.1 
cents  per  linear  foot  or  2.5  cents  per  cu.  yd.,  there  being  no  ram- 
ming of  the  backfill  required.  This  is  a  remarkably  low  cost 
for  backfilling  and  one  not  ordinarily  to  be  counted  upon.  The 
material  was  a  loamy  sand  and  gravel. 

At  Rochester,  N.  Y. — With  the  size  of  trench  and  kind  of  mate- 
rial practically  the  same  results  were  obtained  as  above: 

One  man  excavated  8  cu.  yds.  a  day  at  a  cost  of  19  cents  per 
cu.  yd. ;  1  man  backfilled  16  cu.  yds.  a  day  at  a  cost  of  9  cents 
per  cu.  yd.  Total  cost  of  excavation  and  backfill,  28  cents  per 
cu.  yd. 

Cost  of  Trenching,  Great  Falls,  Mont.— The  Great  Falls 
(Montana)  Water  Co.  excavated  25,500  cu.  yds.  of  earth,  1900  cu. 
yds.  of  loose  rock,  and  1500  cu.  yds.  of  solid  rock  in  trenching 


170  AMERICAN  GAS-ENGINEERING  PRACTICE. 

V 

for  a  6-in.  water-pipe.  The  work  was  done  by  company  labor 
(not  by  contract),  wages  being  $2.25  for  laborers,  and  the  cost 
was  34  cents  per  cu.  yd.  for  excavation  and  3.5  cents  more  per 
cu.  yd.  for  backfilling  and  tamping.  If  wages  had  been  $1.50  a 
day  the  cost  would  have  been  23  cents  per  cu.  yd.  for  excava- 
tion and  2.5  cents  per  cu.  yd.  for  backfilling. 

Cost  of  Trenching,  Astoria,  Oregon. — A.  L.  Adams  states 
that  in  trenching  for  the  Astoria  (Oregon)  Water-works  in  1896 
the  first  contractor  averaged  only  7  to  8  cu.  yds.  per  man 
per  day.  Later  on  another  contractor,  even  in  the  rainy  sea- 
son, averaged  nearly  10  cu.  yds.  per  man  per  10-hour  day  of 
trenching  (including  backfilling)  at  a  cost  (including  foreman) 
of  17.5  cents  per  cu.  yd.,  wages  being  $1.70  a  day.  The  mate- 
rial was  yellow  clay  dug  with  mattocks  and  shovels. 

Cost  of  Trenching,  Hilburn,  N.  Y.— W.  C.  Foster  gives  the 
following  data  on  17,000  ft.  of  trenching  for  water-pipe  at  Hil- 
burn, N.  Y.  The  trench  was  4  ft.  deep  for  4-in.  to  8-in.  pipe. 
The  digging  was  hard,  the  banks  being  full  of  cobbles  and  fre- 
quently caved  in.  The  streets  were  not  paved.  The  cost  of  trench- 
ing and  backfilling  was  10.1  cents  per  lin.  ft.,  wages  being  $1.35 
for  laborers  and  $3  for  foreman. 

Cost  of  Trenching  and  Pipe-laying,  Providence,  R.  I.  —  In 
Engineering  News,  June  28,  1890,  E.  B.  Weston,  Engineer  Water 
Department,  Providence,  R.  I.,  gives  very  full  records  of  pipe- 
laying  costs.  The  tables  on  page  171  are  given  by  him  and  are 
based  upon  many  miles  of  trench- work. 

Wages  in  all  cases  above  were  $1.50  a  day  for  laborers  trench- 
ing and  laying,  $3  a  day  for  foreman,  $2.25  for  calkers,  and  $2.25 
for  teams,  which  probably  refers  to  teams  without  driver.  Carting 
was  in  all  cases  $1  a  ton.  Allowance  for  tools  (item  4)  was  made 
on  a  basis  of  7.25%  of  items  1  and  2. 

Short  lengths,  15  to  50  ft.,  of  6-in.  pipe  cost  34  cents  per  foot 
in  easy  digging  to  45  cents  in  hard  digging  for  excavation,  laying, 
and  backfilling,  wages  being  as  above  stated. 

The  trench  for  a  24-in.  pipe  19,416  ft.  long  and  6.6  ft.  deep 
cost  32  cents  per  cu.  yd.  for  excavation  and  backfill  with  wages 
at  $1.50  a  day. 

A  48-in.  main  was  laid  for  $1.65  per  ft.,  including  digging,  laying, 
calking,  and  backfilling. 

A  16-in.  pipe  374  ft.  long  passed  under  two  railway  tracks, 
and  the  cost  of  trenching,  laying,  and  backfilling  was  50  cents 
per  ft. 

An  8-in.  pipe  was  laid  across  a  bridge,  and  the  cost  of  boxing, 
laying  pipe,  etc.,  was  $1.32  per  ft.,  while  for  a  12-in.  pipe  the 
cost  was  $1.50  per  ft. 


MAINS. 


171 


EASY  DIGGING,  SAND. 


Size  of  Pipe,  In. 

4  • 

6 

8 

10 

12 

16 

20 

1.  Trenching  *..  . 
2.  Laying  

.0422 
.0129 

.0518 
.0162 

.0611 
.0191 

.0707 
.0219 

.0798 
.0249 

.1445 
.0370 

.2088 
.0497 

3.  Foreman  
4.  Tools,  etc.  .  .  . 
5.  Calking  

.0130 
.0041 
.0106 

.0158 
.0050 
.0107 

.0188 
.0059 
.0108 

.0216 
.0069 
.0111 

.0244 
.0078 
.0118 

.0303 
.0134 
.0159 

.0360 
.0191 
0301 

6.  Lead,  Sets.  Ib. 
7  Teams  .  . 

.0224 
0070 

.0320 
0090 

.0431 
0115 

.0553 
0136 

.0683 
0160 

.0950 
0203 

.1203 
0216 

8  Carting  

0078 

0149 

0208 

0275 

0346 

0518 

0746 

9.  Total  

.1200 

.1554 

.1911 

2286 

.2676 

4082 

5602 

MEDIUM  DIGGING,  GRAVEL,  ETC. 


Size  of  Pipe,  In. 

4 

6 

8 

10 

12 

16 

20 

24 

1.  Trenching  *..  . 
2.  Laying  
3.  Foreman  
4;  Tools,  etc.  .  .  . 
5.  Calking  

.0597 
.0189 
.0180 
.0056 
0106 

.0697 
.0220 
.0206 
.0065 
0107 

.0790 
.0249 
.0234 
.0075 
0108 

.0883 
.0279 
.0265 
.0084 
0111 

.0974 
.0307 
.0294 
.0093 
0118 

.1700 
.0440 
.0350 
.0154 
0159 

.2400 
.0577 
.0373 
.0214 
0301 

.3019 
.0639 
.0396 
.0602 
0757 

6.  Lead,  5  cts.  Ib. 
7.  Teams  

.0224 
0070 

.0320 
0090 

.0431 
0115 

.0533 
0136 

.0683 
0160 

.0950 
0203 

.1203 
0216 

.1600 
0228 

8.  Carting  

.0078 

.0149 

.0208 

.0275 

.0346 

.0518 

.0746 

.1317 

9.  Total  

.1500 

.1854 

.2210 

.2586 

.2975 

4474 

6030 

8630 

HARD  DIGGING,  HARD  OR  MOIST  CLAY. 


Size  of  Pipe,  In. 

4 

6 

8 

10 

12 

16 

20 

1.  Trenching  *... 
2  Laying  . 

.0860 
0271 

.0959 
0303 

.1053 
0333 

.1147 
0362 

.1300 
0411 

.2261 
0530 

.3264 
OfifiQ 

3.  Foreman  
4.  Tools,  etc.  .  .  . 
5.  Calking  
6.  Lead,  5  cts.  Ib. 
7.  Teams  

.0260 
.0081 
.0106 
.0224 
.0070 

.0286 
.0090 
.0107 
.0320 
.0090 

.0314 
.0099 
.0108 
.0431 
0115 

.0343 
.0109 
.0111 
.0553 
0136 

.0372 
.0118 
.0118 
.0683 
0160 

.0428 
.0201 
.0159 
.0950 
0203 

.0452 
.0283 
.0301 
.1203 
0216 

8.  Carting  

.0078 

.0149 

.0208 

.0275 

.0346 

.0513 

.0746 

9.  Total.  .  . 

1950 

2304 

2661 

3036 

3508 

5250 

7104 

*  Including  backfilling.     In  all  cases  the  depth  of  the  trench  was  such  that  the  center 
of  the  pipe  was  4  ft.  8  in.  below  ground  surface. 

Trenches  were  ordinarily  2  ft.  wider  than  the  pipe  and  5  ft. 
plus  half  the  diameter  of  the  pipe  deep.  Such  trenches  were 
dug,  the  pipe  laid,  and  backfilling  made  at  the  following  rate  per 
laborer  engaged: 


172  AMERICAN  GAS-ENGINEERING  PRACTICE. 

Diameter  Pipe  Feet  Length 

Inches.  Material.  per  Day. 

6 Easy  earth 21 .0 

6 Medium  earth 17.2 

6 Hard  earth 10.3 

8 Easy  earth 19.3 

12 Medium  earth 13.4 

20 Easy  earth 9.0 

24 Medium  earth 4.4 

Earth  excavation  in  trenches  where  digging  is  easy  cost  20 
cents  per  cu.  yd.;  rock  excavation  averages  $2  per  cu.  yd.,  run- 
ning as  high  as  $3  per  cu.  yd.,  wages  being  $1.50  per  day. 

Where  long  pipe-lines  are  to  be  constructed  a  line  of  levels 
should  first  be  run  and,  the  drip  of  the  pipe  being  taken  into 
account,  the  entire  length  should  be  laid  off  by  the  engineer  in 
convenient  units  of  equal  volume. 

Although  the  quality  of  the  soil,  unforeseen  obstacles,  etc.,  will 
vary  to  some  extent  the  unit  rate  of  progress,  this  will  serve 
as  a  basis  for  the  checking  of  the  progress  of  work  from  day  to 
day  besides  establishing  a  basis  for  the  computing  of  future  oper- 
ations. 

Careful  records  should  be  made  of  the  character  of  the  soil, 
nature  of  obstacles,  etc.,  encountered,  which  should  be  filed  as  a 
portion  of  the  daily  data  and  should  be  ultimately  classified  for 
future  reference. 

The  labor  itself  should  also  be  handled  on  the  unit  basis,  the 
work  being  so  laid  out  in  units  and  decimals  thereof  that  a  check 
can  be  kept  upon  the  individual  output. 

Upon  these  data  (where  not  hampered  by  Unionism)  the  labor 
may  be  classified  under  the  respective  headings  A,  B,  C,  and  D, 
of  which  B  may  represent  the  normal  or  average  and  be  paid 
the  standard  rate  of  wage,  the  normal  being  obtained  either 
from  empiric  data  or  the  immediate  work  done.  A  may  con- 
stitute a  class  of  labor  whose  output  is  in  excess  of  the  average 
or  B  class,  to  whom  a  bonus  of  from  10  to  20  per  cent  should  be 
paid,  depending  upon  their  marginal  efficiency.  It  must  be  re- 
membered, however,  that  in  addition  to  their  work  per  se  these 
men  constitute  the  "  pace-makers "  of  the  force  and  should 
be  paid  accordingly.  Class  C  will  be  formed  of  those  falling 
immediately  below  the  average  and  should  be  constantly  culled 
for  dismissal,  while  all  those  crossing  the  dead-line  between 
Class  C  and  Class  D,  or,  let  us  say,  showing  a  deficiency  of  15% 
helow  the  average  of  Class  B,  should  be  discharged  from  the 
work  at  once. 


MAINS. 


173 


174 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


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MAINS. 


175 


Cost  of  Water=pipe  Laid  at  Alliance,  O  —  L.  L.  Tribus 
gives  the  following  costs  of  work  done  in  1894,  the  material  being 
loam  and  clay  excavated  to  such  a  depth  that  4  ft.  of  earth 
would  be  left  on  top  of  each  class  of  pipe  after  backfilling. 


MATERIAL   USED. 


Size  of  pipe   ins 

4 

6 

8 

10 

12 

Weight  of  pipe,  Ibs.  per  ft.  .  . 
Lbs  specials  per  ft     . 

19 
0  4 

30i 
0.76 

44 
1.1 

62 
1.55 

79 
1.9 

Lbs  lead  per  ft 

0  4 

0.66 

1.0 

1.25 

1.5 

Lbs  yarn  per  ft     

0  02 

0.025 

0.05 

0.08 

0.1 

Total  length  in  ft  

2890 

9760 

1860 

3320 

2930 

COST   PER  LINEAR  FOOT  LAID. 


Size  of  pipe,  ins  
Pipe 

4 
$0  2360 

6 
$0  3780 

8 
$0  .  5350 

10 
$0.7470 

12 
$0  9400 

Specials  and  valves  
Hauling 

.0120 
0056 

.0189 
.0078 

.0268 
.0011 

.0374 
.0145 

.0470 
0190 

Lead                              

.0020 

.0330 

.0500 

.0630 

0750 

Yarn                       

.0014 

.0018 

.0035 

.0056 

0070 

Trenching  

.1240 

.1210 

.1287 

.1480 

1902 

Pipe-laying  

.0370 

.0346 

.0313 

.0542 

0463 

Total  

$0.4360 

SO.  5951 

$0.7764 

$1.0697 

$1  3245 

This  work  was  done  by  laborers  and  men  employed  by  the 
water  company  and  does  not  include  cost  of  superintendence. 
The  4-ft.  cover  over  the  pipe  was  in  some  cases  exceeded.  The 
digging  was  comparatively  easy  with  little  ground-water  to  bother. 
Mr.  Tribus  informs  me  that  the  wages  paid  were:  Laborers,  $1.25; 
pipe-haulers,  $1.50;  and  calkers,  $2.25,  per  10-hour  day. 

Cost  of  Water=pipe  Laid  in  a  Southern  City. — In  En- 
gineering News,  March  30,  1893,  C.  D.  Barstow  gives  very  com- 
plete tables  of  cost  of  shallow  trenching  and  pipe-laying  in  a 
Southern  city,  where  negro  laborers  were  used.  From  the  data 
given  by  him  I  have  compiled  the  following  table  of  cost. 

For  the  most  part  the  trenches  were  15  in.  wide  at  bottom  and 
20  in.  at  top,  and  3  ft.  deep.  Some  trenching  was  done  using  a 
team  on  a  drag  scraper,  20  in.  wide;  then  the  trench  was  made  3  ft. 
at  top.  After  a  rain,  however,  the  scrapers  could  not  be  used  to 
advantage.  In  using  a  plow  for  loosening  the  earth,  several  feet 
of  chain  are  fastened  to  the  end  of  the  plow-beam,  and  one  or 
more  men  ride  the  beam;  in  this  way  plowing  may  be  done  in  a 
trench  4  ft.  deep,  one  horse  walking  on  one  side  and  one  on  the 
other  side  of  the  trench,  A  blacksmith  was  kept  busy  sharpening 


176 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


about  60  picks  a  day.     There  was  a  night-watchman.     The  pipe 
was  distributed  by  contract  at  34  cents  per  ton. 

TABLE  OF  COST  OF  TRENCHING  AND  PIPELAYING  IN  THE  SOUTH. 

Wages  per  10-hour  day  for  negro  laborers,  $1.25;  for  calkers,  $1.75;  for 
white  foreman,  $3.00  ;  for  teams,  $3.25  ;  for  horse  ridden  by  boy,  $1  50. 


Job. 

A. 

B. 

C. 

D. 

E. 

F. 

Pipe  ins 

10  1 

6 

8 

10 

88 

Length  ft  

11,000 

6,000 

6,215 

11  352 

2639 

21  856 

Width  trench,  ft  

2 

Depth  trench,  ft  

3  5 

3 

3 

3 

3 

3 

Material  

2 

4 

0 

Number  laborers  digging. 
Number  teams  plowing 

33 

30 

40 

31 

3i 

45 
5 

46 
2i 

Team  time  cts  per  ft  . 

0  80 

0  62 

0  60 

Labor,  digging,  cts.  per  ft. 
Foreman,  digging,  cts.  ft. 
Labor,  pipe-laying,  cts.ft. 
Foreman,  pipe-laying,  cts. 
ft  
Bell-hole  digging,  cts.  ft.  . 
Bell-hole    digging,    fore- 
man, cts.  per  ft  
Calking  cts  per  ft 

6.66 
0.50 
2.04 

0.39 
2.70 

0.27 
1  30 

2.74 
0.23 

5.19 
0.31 
0.63 

0.17 
0.77 

0.16 
0  52 

2.68 
0.21 
0.77 

0.21 

0.98 

0.21 

0  t4 

2.12 
0.12 
0.94 

0.18 
0.93 

0.18 
0  63 

4.00 
0.20 
1.12 

0.24 
1.16 

0.18 
0  75 

Backfill  and  tamping  : 
Labor,  cts.  per  ft  
Foreman,*  cts.  per  ft.  ... 
Team,*  cts.  per  ft  

4.323 
0.36 

l.OO5 
0.22 

1.016 
0.22 
0.36 

2.09 
0.32 

1.427 
0.18 

0.95° 
0.18 
0  41 

Horse  ridden  by  boy,  cts. 
per  ft  
Total  cost,  cts.  per  ft.  ... 

18.54. 

4.19 

0.07 
9.45 

8.91 

0.09 
7.41 

"9.79" 

The  lead  and  yarn  consumed  per  foot  of  pipe  (length  12  ft.)  was: 
1.3  Ibs.  of  lead  and  0.04  Ib.  of  hemp,  for  12-in  pipe; 
0.96  Ib.     "     "      "    0.04  "     "      "        "  10-in.    " 
0.95    "     "     "      "     0.03  "     "      "        "     8-in.     " 
0.66    "     "     "      "    0.02  "     "      u        "     6-in.     " 

*  Backfill  with  drag  scraper. 

1  Trenching  in   an   old  street,   1200  ft.  in  very  muddy  ground.     Two  rainy  spells  in 
18  days  of  work.     Then  10-in.  pipe  was  laid  for  3440  ft.;    then  4038  ft.  of   12-in.  pipe 
were  laid  for  H  cts.  per  foot  less  than  it  cost  for  the  10-in.  pipe;    then  3270  ft.  of  8-in. 
pipe  were  laid  for  2i  cts.  per  foot  less  than  it  cost  for  the  10-in. 

2  Cemented  clay  and  gravel  requiring  hard  picking.     Frequent  rains. 

3  The  backfilling  and  tamping  done  most   thoroughly,  a  stretch  of  2550  ft.  requiring 
3  days  for  30  men. 

4  Sand  and  loam,  bottom  land,  very  easy  digging. 

6  Very  little  shoveling  and  no  tamping;    11  men  in  7  days  backfilled  9620  ft.  of  trench. 
c  Drag  scrapers  used  to  backfill;    boy  riding  horses  to  tamp,  gang  22  men,*  3  teams, 

1  boy,  and  horse,  2  days  on  5447  ft. 

7  Backfilled  1670  ft.  in  one  day  by  19  men,  using  one  boy  and  horse  on  tamping. 

8  Half  the  pipe  was  8  in.  at  cost  here  given,  half  was  6  in.  costing  less  for  laying. 

9  Ground  wet  and  often  muddy.     Backfilling  11,433  ft.  done  by  12  men  and  2  teams 
on  scrapers  in  7  days;   no  tamping. 


MAINS. 


177 


Some  6000  ft.  of  2-in.  wrought-iron  service  pipe  were  laid  in 
2  ft.  deep  trenches  at  a  trenching  cost  of  1.9  cts.,  laying  0.24  cts., 
backfilling  0.71  cts.,  without  tamping. 


Removing  brick  and  concrete. 

Excavating  trench 

Backfilling  and  tamping  well. 


Labor  relaying  concrete 

bricks 

Professional  brick-pavers 

brick-helpers 

Hauling  away  23  loads  surplus  earth. 

15  cu.  yds.  sand  cushion 

1700  new  bricks 

18  bbls.  cement  to  relay  concrete.  . . . 


Foreman 
Laborers 
Foreman 
Laborers 
Foreman 
Laborers 


Men, 
Days. 

0.5 

7.0 

0.5 
18.0 

1.0 
10.6 

7.8 

4.5] 

4.0  y 

2.0J 


Total. 


Cents  per 
Linear  Foot 

2.61 
6.30 

4.09 
2.61 

4.59 

1.23 
4.02 
6.92 
6.20 

38.58 


Cost  of  Taking  Up  an  Old  Pipeline.— E.  E.  Fitzpatrick  fur- 
nishes the  following  data  relative  to  taking  up  more  than  3  miles 
of  pipe-line  in  Greenburg,  Kansas.  There  were  10,200  ft.  of 
4-in.  pipe,  4310  ft.  of  6-in.,  2050  ft.  of  8-in.,  and  890  ft.  of  10-in. 
After  digging  the  trenches  the  8-in.  and  10-in.  pipes  were  raised 
a  little  and  fires  built  under  the  joints  until  the  pipe  expanded; 
then  the  pipes  were  un jointed  by  working  them  up  and  down  with 
a  three-leg  derrick.  The  4-in.  and  6-in.  pipes  were  raised  bodily 
in  long  sections  onto  the  bank,  heated  a  little,  and  unjointed  by 
means  of  jack-screws  and  clamps.  The  time  required  to  do  all 
the  trenching,  backfilling,  and  unjointing  was  equivalent  to  the 
work  of  one  man  for  425  days;  and,  assuming  wages  at  $1.50  a 
day,  the  cost  was  only  3f  cts.  per  foot  of  pipe. 

Cost  of  Subaqueous  Pipe=laying. — A  line  of  12-in.  water-pipe 
was  laid  in  a  trench  dredged  across  a  river  500  ft.  wide,  as  follows: 
The  water  in  the  river  averaged  4  ft.  deep,  and  the  trench  was  dug 
6  ft.  deep,  making  a  depth  of  10  ft.  from  water  surface  to  bottom 
of  the  trench.  To  lower  the  pipe  into  the  trench  A-frame  bents 
were  built  of  4  X  6-in.  timber,  the  legs  of  the  bents  straddling  the 
trench,  and  each  pipe  was  supported  by  an  iron  rod  passing  through 
a  hole  bored  in  the  horizontal  member  of  the  A  frame.  These 
rods  were  about  12  ft.  long,  f  in.  diameter,  and  threaded  their 
full  length.  Each  rod  was  provided  with  a  hook  at  its  lower  end 
to  hook  into  an  iron  ring  around  the  pipe.  The  pipe  was  ordinary 
cast-iron  pipe,  and  was  leaded  and  calked  while  suspended  from 
the  A  frames.  Then  it  was  the  intention  to  lower  the  500  ft.  of 


178  AMERICAN  GAS-ENGINEERING  PRACTICE. 

pipe  all  at  one  time  by  putting  a  man  with  a  monkey-wrench  at 
each  rod,  to  give  the  nut  on  the  rod  a  turn  at  a  given  signal  from 
a  whistle.  There  were  43  bents,  12  ft.  apart,  and  it  was  decided 
that  a  force  of  10  men  could  lower  the  pipe  satisfactorily  by  giving 
a  few  turns  of  the  nuts  on  10  rods,  then  moving  to  the  next  10 
rods,  and  so  on.  Through  carelessness  or  mischief,  some  of  the 
men  gave  more  turns  to  the  nuts  than  the  signals  called  for.  This 
threw  the  weight  of  several  pipes  upon  one  or  more  rods,  and  broke 
one  of  them  at  the  hook,  which  was  the  weak  spot.  Immediately 
all  the  other  rods  broke  in  rapid  succession,  dropping  the  pipe-line 
into  the  river.  The  pipe  settled  to  the  bottom  without  breaking 
in  two  anywhere,  and  only  one  joint  showed  any  leakage  when 
inspected  immediately  after  the  accident.  This  joint  was  calked 
by  a  man  who  dived  down  repeatedly,  and  struck  a  few  blows 
each  time.  However,  the  diver  was  sent  to  examine  every  joint, 
and  inspection  showed  the  pipe-line  to  be  intact  from  end  to  end. 
The  cost  of  building  the  A  frames,  placing  and  calking  the  pipe- 
line, was  as  follows: 

10  men,  3  days,  at  $1.75 $52.50 

1  foreman,  3  days,  at  $3.00 9.00 

10  men,  1  day  at  work  lowering  pipe,  at  $1.75 17.50 

.  1  foreman,  1  day  at  work  lowering  pipe,  at  $3.00. .  3.00 

1  diver,  1  day  inspecting  line 25 . 00 

Traveling  expenses  of  diver 15.00 

Total  for  516  ft.  of  pipe $122.00 

The  above  does  not  include  the  cost  of  the  iron  rods,  nor  the 
timber  used  in  the  bents,  nor  the  building  of  a  small  raft  from 
which  to  erect  the  A-frame  bents. 

From  this  experience  I  believe  it  would  be  safe  to  dispense 
with  the  threaded  iron  rods  for  lowering  such  a  line  of  pipe.  The 
pipe  could  be  held  just  above  the  water  surface  by  small  manila 
ropes  until  calked.  Then  upon  cutting  one  or  two  of  the  ropes 
the  rest  would  break  and  allow  the  pipe  to  settle  into  the  water. 
As  the  pipe-line  is  quite  buoyant  when  filled  with  air  it  settles 
down  gently  upon  the  bottom  of  the  trench.  In  case  a  break 
should  occur  in  the  line,  threaded  rods  could  be  made  and  the  pipe 
raised  and  repairs  made  at  but  slightly  greater  expense  than  would 
have  been  incurred  had  rods  been  used  in  the  first  place.  When 
pipe  is  lowered  as  above  described,  one  flexible  pipe-joint  is  usually 
provided  at  each  end  of  the  pipe-line. 

Cost  of  Laying  Pipe  Across  the  Susquehanna. — James  P. 
Herdic  gives  the  following  data  relating  to  laying  10-in.  iron  pipe 


MAINS.  179 

across  the  Susquehanna  River  at  Montoursville,  Pa.,  a  distance  of 
600  ft.,  the  average  depth  of  water  being  13  ft.  A  J-in.  manila 
rope  was  first  stretched  across  the  river,  to  act  as  a  ferry-line  for 
the  scows.  The  scows  were  loaded  with  pipe.  The  crew  of  eight 
men  and  foreman  were  engaged  1  day  in  this  preliminary  work, 
and  then  laid  the  600  ft.  of  pipe-line  in  the  next  2£  days.  One 
ball-and-socket  joint  was  used  to  every  six  ordinary  joints.  The 
pipe-line  was  lowered  between  two  scows  by  means  of  chain  pul- 
leys suspended  from  a  heavy  sawhorse  that  spanned  the  gap 
between  the  two  boats.  The  pipe  was  laid  in  a  gentle  curve, 
bowed  up-stream,  so  as  to  form  an  arch  to  resist  the  stronger  cur- 
rents. 

In  an  instance  on  the  Susquehanna  River,  also  described  in 
Gillette's  excellent  Handbook,  where  the  current  was  sufficiently 
swift  to  swamp  a  scow  if  handled  by  the  above  method,  the  scow 
was  held  in  the  current  at  an  angle  to  its  flow,  nose  up-stream, 
ropes  being  anchored  from  bow  and  stern  to  nearest  shore  in  such 
a  manner  that  the  force  of  the  current  kept  the  ropes  taut.  The 
pipe  lay  across  the  middle  of  the  scow,  which  was  moved  out  from 
under  the  line  as  fast  as  each  joint  was  made  up.  Six  common 
joints  to  each  ball  and  socket  were  used. 

Cost  of  Laying  6=in.  Pipe  Under  Water.— Still  another  Gil- 
lette record  is  as  follows:  About  5100  ft.  of  6-in.  pipe  were  laid 
from  the  New  Jersey  shore  to  Ellis  Island,  the  depth  of  water 
being  from  10  to  17  ft.  A  trench  was  dug  5  ft.  deep  by  10  ft. 
wide  in  the  mud,  using  a  clam-shell  bucket.  Heavy  pipe,  weigh- 
ing 800  Ibs.  per  length,  with  Ward  flexible  joints  was  used.  Two 
scows  26X80  ft.  each  were  fastened  together  at  a  distance  of  6  ft., 
and  were  provided  with  two  skids  of  10X10  timbers  55  ft.  long, 
leading  down  between  the  scows  to  the  bottom  of  the  trench. 
The  skids  could  be  lowered  in  rough  weather.  Two  lengths  of 
pipe  were  placed  by  a  derrick  upon  the  skids  at  one  time,  these 
being  made  up,  and  the  scows  were  warped  ahead  24  ft.  This 
work,  with  a  force  of  ten  laborers,  two  calkers,  and  one  diver, 
required  just  one  month. 

Cost  of  Laying  Pipe  Across  the  Willamette  River. — The 
Engineering  Record  of  Sept.  19  and  26,  1897,  records  the  laying 
of  a  32-in.  pipe  across  the  Willamette  River,  Oregon:  Two  scows 
and  an  inclined  cradle  were  used.  The  force  was  sixteen  men  and 
one  diver.  They  laid  80  ft.  of  pipe  per  day  in  a  trench  23  ft. 
below  the  surface  of  the  water. 

Designating  Crosses. — In  ordering  reducing  tees,  it  becomes 
necessary  to  name  the  run  and  outlet.  Fig.  I  illustrates  diagram- 
matic ally  the  run  and  outlet  and  shows  the  tee  reducing  on  the 
outlet.  Such  a  tee  is  read  2X1J  ins.  The  run  is  read  first.  In 


180  AMERICAN  GAS-ENGINEERING   PRACTICE. 

ordering  tees  that  reduce  on  the  run  we  say  2x  1-|  X  1|  ins.,  as  shown 
in  Fig.  II.  Whenever  both  ends  of  the  run  are  of  the  same  size, 
but  having  the  outlet  larger,  such  a  tee  is  called  bull-head  and  is 
read  1^X2  ins.,  as  shown  in  Fig.  III.  It  will  be  seen  that  when  a 
tee  reduces  on  the  run,  we  will  have  three  figures  to  specify ;  whereas, 
if  a  tee  reduces  on  the  outlet,  we  have  but  two  figures  to  indicate. 
Thus,  in  tees  reducing  on  the  run,  we  have  ^XfXi  ins.;  reducing 
an  outlet,  we  have  IX  j  ins.  In  like  manner,  in  ordering  crosses, 

li"  2" 


2"__1___2"  2"  I  U" 


FIG.  I.  FIG.  II.  FIG.  III. 

2"  i" 


3". 


.3" 


.a* 


2"  1" 

FIG.  IV.  FIG.  V. 

the  size  of  outlet  or  run  must  be  particularly  stated.  A  very  im- 
portant rule  about  crosses  is  as  follows:  The  outlets  of  a  cross  are 
always  of  the  same  size,  and  indicated  by  the  last  figures.  By 
referring  to  Fig.  IV,  it  will  be  seen  that  the  outlets  are  2  ins.,  while 
the  run  is  3  ins. ;  but,  since  the  outlets  of  a  cross  are  always  of  the 
same  size,  it  follows  that  a  reducing  cross  must  reduce  on  the  run. 
A  cross  l^XHXl  in.  shows  the  outlets  are  1  in.,  while  the  run  is 
IJXli  ins.  It  should  be  remembered  that  crosses  are  read  on  the 
run  first,  and  when  reducing  on  the  run  three  figures  are  to  be 
mentioned ;  when  reducing  on  the  oulets  two  figures  are  to  be  indi- 
cated. 

Lead=wool  Joints. — The  use  of  this  material  in  the  jointing 
of  cast-iron  pipe  will  be  found  under  many  conditions  most  con- 
venient and  satisfactory.  The  enormous  strength  of  the  joints 
produced  and  their  freedom  from  leakage,  due  to  their  homogeneous 
structure,  make  them  especially  adaptable  for  high-pressure  service. 

These  joints  are  also  excellent  for  submarine  work,  inasmuch 
as  they  may  be  made  up  under  water,  and  more  especially  because 
of  the  tremendous  flexibility  rendered  the  pipe-line  by  their  use; 
in  this  connection  experiments  have  shown  a  deflection  in  a  bell- 
and-spigot  joint  of  16°  12'  without  leakage  under  a  pressure  of 
2000  Ibs.,  effecting  an  excellent  arrangement  where  any  pipe-line 
is  subject  to  vibrations,  strains,  or  deflections.  The  joints  are 
practically  unaffected  by  the  bending  or  settling  of  the  pipe-line. 


MAINS.  181 

Lead  wool  is  lead  cut  in  fine  fibers.  These  fibers  are  put  into 
the  joint  in  the  same  way  as  yarn.  The  lead  is  being  calked  from 
the  yarn  up,  not  only  at  the  outside.  The  result  is  an  absolutely 
tight,  perfect  joint  that  will  never  leak. 

The  lead  being  calked  in  cold,  obviates  the  loss  in  fit  due  to 
the  shrinkage  of  the  casting  in  the  contraction  of  cooling.  The 
following  general  claims  are  made  for  it: 

No  melting  of  lead;  no  waste  of  material;  calking  may  be  done 
in  wet  grounds  or  on  rainy  days;  joints  may  be  made  up  and  calked 
under  water. 

AMOUNT   OF    LEAD    WOOL   NECESSARY   FOR   VARIOUS    JOINTS. 

Size  of  joint.  .  .....  3"    4"    6"    8"     10"     12"     16"    20"    24"    30"    36" 

Pounds  of  cast  lead 

used  ............  5      6      9     13       17      20      30      40      65       90     103 

Pounds  of  lead  wool 

used  ..............     .  .       6     10       12       14      20      28      40      65       65 

Owing  to  the  fact  that  every  ounce  of  lead  that  goes  into  the 
joint  is  calked  by  using  lead  wool,  whereas  the  cast  lead  joint  can 
be  calked  to  the  depth  of  about  half  an  inch  only,  we  advise  the 
putting  in  of  lead  wool  to  the  depth  of 

inch  on  all  joints  up  to    6  inches. 

I  9          (  ( 


Concerning  the  cost  of  lead  wool,  which  is  about  12  cents  per 
pound  in  ton  lots,  which  would  increase  the  cost  considerably  if 
the  same  quantity  of  lead  wool  were  used.  It  will  be  seen  from  the 
figures  that  this  is  not  necessary  and  that  the  amount  of  lead  wool 
necessary  is  a  good  deal  less  than  that  of  cast  lead. 

The  strength  of  a  lead-wool  joint  is  immensely  superior  to  any 
other  made.  The  Mannesman  Seamless  Tube  Co.  have  successfully 
tested  lead-wool  joints  on  a  pressure  of  over  4000  Ibs.  It  is  a  safe 
statement,  therefore,  that  a  lead-wool  joint  will  hold  a  much  greater 
pressure  than  cast-iron  pipe. 

Directions  for  Using  Lead  Wool 

No.  1  and  2  calking  tools  should  be  made  with  a  dull  triangular 
point  instead  of  a  square. 

Have  one  leg  of  the  edge  made  slightly  shorter  than  the  other, 
and  use  the  shorter  end  against  the  spigot.  This  will  drive  the 
lead  well  up  into  the  crease. 

The  trimming  tools  remain  square. 

In  calking  joints  with  lead  wool  the  most  important  point  is  to 
hammer  in  each  layer  of  fibers  as  hard  and  tight  as  possible. 


182 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


Unless  the  lead  wool  be  calked  solidly  from  the  bottom  up,  it 
will  not  hold  better  than  a  cast  joint. 

Tar  oakum  is  preferable  to  dry  oakum,  because  the  lead  wool 
will  better  adhere  to  it. 

The  strands  of  lead  wool  are  put  in  one  at  a  time;  each  strand 
should  be  calked  separately. 

The  lead  wool  need  not  extend  beyond  the  crease.  This  means 
a  great  saving  of  lead.  Up  to  the  crease  the  joint  is  calked  with 
yarn. 

MAIN  SPECIALS. 


QUARTER  BENDS. 


Size. 

Thickness  of 
Metal. 

A 

C 

R 

4 

.40 

4.50 

15.00 

3.00 

6 

.43 

6.25 

16.50 

4.50 

8 

.46 

8.00 

18.00 

6.00 

10 

.49 

9.75 

19.50 

7.50 

12 

.54 

11.25 

21.00 

9.00 

16 

.60 

14.50 

24.00 

12.00 

20 

.67 

17.75 

27.00 

15.00 

24 

.76 

21.00 

30.00 

18.00 

LARGE    HUB    AND    SPIGOT   QUARTER   BENDS. 


Size. 

Thickness  of 
Metal. 

R 

S 

K 

24 

.76 

30 

12 

42.4 

30 

.88 

36 

12 

50.9 

36 

.99 

48 

12 

67.9 

42 

1.10 

60 

12 

84.8 

48 

1.26 

66 

12 

93.32 

MAINS. 


183 


HUB    SLEEVE. 


Size. 

Thickness. 

A 

B 

H 

J 

S 

10X   4 

.49 

12.10 

6.55 

15 

3.00 

4.00 

10X   5 

.49 

12.10 

6.55 

18 

3.00 

6.00 

12X   4 

.54 

14.20 

7.64 

15 

3.00 

4.00 

12X   6 

.54 

14.20 

7.64 

18 

3.00 

6.00 

16X   6 

.60 

18.30 

9.80 

18 

3.75 

6.00 

16X  8 

.60 

18.30 

9.80 

18 

3.75 

8.00 

20X   6 

.67 

22.59 

11.97 

18 

3.75 

6.80 

20X   8 

.67 

22.59 

11.97 

18 

3.75 

8.00 

20X10 

.67 

22.59 

11.97 

18 

3.75 

10.00 

SERVICE   SLEEVE. 


Size. 

Thickness  of 
Metal. 

A 

B 

H 

J 

T 

2 

.38 

3.38 

2.35 

8 

2.75 

1.25 

2 

.38 

3.38 

2.35 

8 

2.75 

1.50 

3 

.38 

4.80 

3.40 

12 

2.75 

1.25 

3 

.38 

4.80 

3.40 

12 

2.75 

1.50 

4 

.40 

5.80 

3.85 

12 

2.75 

2.00 

6 

.43 

7.90 

5.27 

12 

2.75 

3.00 

8 

.46 

10.05 

6.37 

12 

3.00 

3.00 

184 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


SOLID    SLEEVE. 


Size. 

Thickness  of 
Metal. 

A 

H 

2 

.38 

3.38 

8 

3 

.38 

4.80 

12 

4 

.40 

5.80 

12 

6 

.43 

7.90 

12 

8 

.46 

10.05 

15 

10 

.49 

12.10 

15 

12 

.54 

14.20 

15 

16 

.60 

18.30 

18 

20 

.67 

22.59 

18 

24 

.76 

26.77 

18 

30 

.88 

32.99 

18 

36 

.99 

39.21 

18 

42 

1.10 

45.45 

18 

48 

1.26 

51.75 

18 

BUSHINGS. 


Size. 

A 

B 

C 

H 

6X   3 

4.60 

6.65 

6.90 

4.5 

6X  4 

5.80 

6.65 

6.90 

4.5 

8X  4 

5.80 

8.80 

9.05 

4.5 

8X   6 

7.90 

8.80 

9.05 

4.5 

10X   6 

7.90 

10.85 

11.10 

4.5 

10X  8 

10.05 

10.85 

11.10 

4.5 

12X  6 

7.90 

12.95       . 

13.20 

5.0 

12X  8 

10.05 

12.95 

13.20 

5.0 

12X10 

12.10 

12.95 

13.20 

5.0 

MAINS. 


185 


PLUGS. 


Size. 

A 

G 

H 

Q 

3 

3.80 

.40 

5.25 

4.0 

4 

4.80 

.40 

5.25 

4.0 

6 

6.90 

.43 

5.25 

6.0 

8 

9.05 

.46 

5.25 

8.0 

10 

11.10 

.49 

5.25 

10.0 

12 

13.20 

.54 

6.00 

12.0 

16 

17.20 

.60 

6.00 

22.0 

20 

21.34 

.67 

6.00 

36.0 

24 

25.52 

.76 

6.50 

60.0 

30 

31.74 

.88 

6.50 

78.0 

36 

37.96 

.99 

6.50 

90.0 

42 

44.20 

1.10 

6.50 

120.0 

48 

50.50 

1.26 

6.50 

150.0 

f=l 


FLANGED   PIPES. 


Size. 

Diameter, 
Flange. 

Thickness, 
Flange. 

Diameter, 
Bolt  Circular. 

Number  of 
Bolts. 

Size  of 
Bolts. 

Thickness, 
Pipe. 

4 

9.0 

.72 

7.125 

4 

.625 

.40 

6 

11.0 

.77 

9.125 

4 

.625 

.43 

8 

13.5 

.81 

11.125 

8 

.625 

.46 

10 

16.0 

.86 

13.75 

8 

.625 

.49 

12 

19.0 

.93 

15.75 

8 

.625 

.54 

16 

22.5 

1.00 

20.00 

12 

.750 

.60 

20 

27.0 

1.00 

24.50 

16 

.750 

.67 

24 

31.0 

.125 

28.50 

16 

.750 

.76 

30 

37.5 

.25 

35.00 

20 

.875 

.88 

36 

44.0 

.375 

41.25 

«    24 

.875 

.99 

42 

50.75 

.56 

47.75 

28 

1.00 

1.10 

48 

57.00 

.75 

54.00 

32 

1.00 

1.26 

186 


AMERICAN   GAS-ENGINEERING  PRACTICE. 


CAPS. 


Size. 

D 

F 

O 

3 

4.80 

4.00 

.40 

4 

5.80 

4.00 

.40 

6 

7.90 

4.00 

.43 

8 

10.05 

4.00 

.46 

10 

12.10 

4.00 

.49 

12 

14.20 

4.50 

.54 

16 

18.30 

4.50 

.60 

20 

22.59 

4.50 

.67 

24 

26.77 

5.00 

.76 

30 

32.99 

5.00 

.88 

36 

39.21 

5.00 

.99 

42 

45.45 

5.00 

1.10 

48 

51.75 

5.00 

1.26 

SPLIT   SLEEVES. 


Size. 

Thickness, 
C 

A 

H 

J 

Number  of 
Bolts. 

Diameter, 
Bolts. 

2 

.38 

3.38 

8.0 

2.75 

4 

.75- 

3 

.38 

4.80 

12.0 

2.75 

6 

.75 

4 

.40 

5.80 

12.0 

2.75 

6 

.75 

6 

.43 

7.90 

12.0 

2.75 

6 

.75 

8 

.46 

10.05 

15.0 

3.00 

8 

.75 

10 

.49 

12.10 

15.0 

3.00 

8 

.75 

12 

.54 

14.20 

15.0 

3.00 

8 

.75 

16 

.60 

18.30 

18.0 

3.75 

10 

.875 

20 

.67 

22.59 

18.0 

3.75 

10 

.875 

24 

.76 

26.77 

18.0 

3.75 

10 

.875 

30 

.88 

32.99 

18.0 

3.75 

10 

.875 

36 

.99 

39.21 

18.0 

4.50 

10 

1.00 

42 

1.10 

45.45 

18.0 

4.50 

10 

1.00 

48 

1.26 

51.75 

18.0 

4  .  50 

10 

1  .00 

MAINS. 


187 


HAT    FLANGE. 


Size. 

Thickness 
of  Metal. 

D 

R 

H 

C 

24X   6 

.43 

6 

13.0 

4 

13.50 

24X   8 

.46 

8 

13.0 

4 

15.50 

24X10 

.49 

10 

13.0 

4 

17.50 

24X12 

.54 

12 

13.0 

4 

19.50 

SOX   6 

.43 

6 

16.0 

4 

13.50 

SOX  8 

.46 

8 

16.0 

4 

15.50 

30X10 

.49 

10 

16.0 

4 

17.50 

30X12 

.54 

12 

16.0 

4 

;      19.50 

36X   6 

.43 

6 

19.25 

4 

13.50 

36X   8 

.46 

8 

19.25 

4 

15.50 

36X10 

.49 

10 

19.25 

4 

17.50 

36X12 

.54 

12 

19.25 

4 

19.50 

42X   6 

.43 

6 

22.37 

4 

13.50 

42X   8 

.46 

8 

22.37 

4 

15.50 

42X10 

.49 

10 

22.37 

4 

17.50 

42X12 

.54 

12 

22.37 

4 

19.50 

48X   6 

.43 

6 

25.5 

4 

13.50 

48X   8 

.46 

8 

25.5 

4 

15.50 

48X10 

.49 

10 

25.5 

4 

17.50 

48X12 

.54 

12 

25.5 

4 

19.50 

188 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


ONE-EIGHTH  BEND. 


Size. 

Thickness  of 
Metal. 

A 

C 

R 

4 

.40 

3.16 

20.5 

4 

6 

.43 

4.23 

21.5 

6 

8 

.46 

5.31 

22.25 

8 

10 

.49 

6.39 

23.00 

10 

12 

.54 

7.22 

24.00 

12 

16 

.60 

9.12 

25.00 

16 

20 

.67 

11.03 

27.25 

20 

24 

.76 

12.94 

29.00 

24 

30 

.88 

15.67 

31.50 

30 

ONE-EIGHTH   BEND. 


Size. 

Thickness  of 
Metal. 

A 

R 

Diameter, 
Flange. 

Thickness, 
Flange. 

4 

.40 

3.42 

2 

9 

.72 

6 

.43 

4.23 

3 

11 

.77 

8 

.46 

5.63 

3 

13.5 

.81 

10 

.49 

5.44 

4 

16 

.86 

12 

.54 

5.82 

4 

19 

.93 

16 

.60 

6.62 

4 

22.5 

1.00 

20 

.67 

8.82 

5 

27 

1.00 

24 

.76 

9.59 

5 

31 

1.125 

30 

.88 

11.76 

5 

37.5 

1.250 

36 

.99 

14.65 

5.5 

44 

1.375 

42 

1.10 

15.83 

5.5 

50.75 

1.560 

48 

1.26 

16.97 

5.5 

57 

1.750 

MAINS. 


189 


ONE-EIGHTH   BEND. 


Size. 

Thickness  of 
Metal. 

A 

B 

R 

4 

.40 

13.65 

3.15 

4 

6 

.43 

14.48 

4.23 

6 

8 

.46 

15.31 

5.31 

8 

10 

.49 

16.14 

6.39 

10 

12 

.54 

16.97 

7.22 

12 

ONE-EIGHTH  BEND. 


Size. 

Thickness  of 
Metal. 

K 

R 

20 

.67 

36.70 

48 

24 

.76 

45.90 

60 

30 

.88 

45.90 

60 

36 

.99 

68.90 

90 

42 

1.10 

68.90 

90 

48 

1.26 

68.90 

90 

190 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


BELLS. 


Size. 

Thickness 
of  Metal. 

Distance 
A 

Distance 
B 

Distance 
C 

Diam. 

Depth. 

Ext. 

Diam. 

4X   4 

.40 

8 

8 

20 

5.8 

4.0 

8.4 

6X   4 

.43 

8 

8 

20 

7.9 

4.0 

10.7 

6X   4 

.40 

8 

8 

20 

8X  8 

.46 

10 

10 

22 

10.05 

4.0 

13.05 

8X  6 

.43 

10 

10 

22 

8X  4 

.40 

10 

10 

22 

10X10 

.49 

12 

12 

24 

12.10 

4.0 

15.10 

10X  8 

.46 

12 

12 

24 

10X   6 

.43 

12 

12 

24 

10X   4 

.40 

12 

11 

24 

12X12 

.54 

14 

14 

26 

14.2 

4.5 

17.4 

12X10 

.49 

14 

14 

26 

12X  8 

.46 

14 

13 

26 

12X  6 

.43 

14 

13 

26 

12X   4 

.40 

14 

13 

26 

16X16 

.60 

17 

17 

29 

18.3 

4.5 

21.9 

16X12 

.54 

17 

17 

29 

16X10 

.49 

17 

16 

29 

16X   8 

.46 

17 

15.5 

29 

16X   6 

.43 

17 

15.5 

29 

20X20 

.67 

19 

19 

31 

22.59 

4.5 

26.6 

20X16 

.60 

19 

19 

31 

20X12 

.54 

19 

17 

31 

20X10 

.49 

19 

17 

31 

20X  8 

.46 

19 

16 

31 

24X24 

.76 

21 

21 

33 

26.77 

5.00 

31.0 

24X20 

.67 

21 

21 

33 

24X16 

.60 

21 

21 

33 

24X12 

.54 

21 

20 

33 

24X10 

.49 

21 

19 

33 

MAINS. 


191 


BE  LLS — Continued. 


Size. 

Thickness 
of  Metal. 

Distance 
A 

Distance 
B 

Distance 
C 

Diam. 

Depth. 

Ext. 
Diam. 

30X30 

.88 

26 

26 

41 

32.99 

5.00 

37.6 

30X24 

.76 

23 

24 

36 

30X20 

.67 

21 

24 

•34 

30X16 

.60 

19 

24 

29 

30X12 

.54 

15 

23 

27 

36X36 

.99 

29 

29 

44 

39.21 

5.00 

44.21 

36X30 

.88 

26 

27 

41 

36X24 

.76 

23 

27 

36 

36X20 

.67 

21 

27 

34 

36X16 

.60 

19 

26 

29 

42X42 

1.10 

32 

32 

47 

45.45 

5.00 

51.05 

42X36 

.99 

29 

30 

44 

42X30 

.88 

26 

30 

41 

42X24 

.76 

23 

30 

36 

42X20 

.67 

21 

30 

34 

48X48 

1.26 

35 

35 

50 

51.75 

5.00 

57.75 

48X42 

1.10 

32 

33 

48 

48X36 

.99 

29 

33 

44 

48X30 

.88 

26 

33 

41 

48X24 

.76 

23 

33 

36 

REDUCERS. 


Size. 

Thickness 
C 

Thickness 
D 

H 

/ 

K 

7 

14X   6 

.57 

.46 

20 

4.0 

8 

32 

14  X   4 

.57 

.40 

20 

4.0 

8 

32 

18X10 

.64 

.49 

20 

4.0 

8 

32 

18  X   8 

.64 

.46 

20 

4.0 

8 

32 

24X12 

.76 

.54 

26 

3.5 

8 

37.5 

30X24 

.88 

.76 

26 

3.0 

8 

37 

30X20 

.88 

.67 

26 

3.5 

8 

37.5 

30X16 

.88 

.60 

26 

3.5 

8 

37.5 

36X30 

.99 

.88 

32 

3.0 

8 

43 

42X36 

1.10 

.99 

32 

3.0 

8 

43 

48X42 

1.26 

1.10 

32 

3.0 

8 

43 

54X48 

1.35 

1.26 

32 

3.0 

8 

43 

192 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


DIMENSIONS. 


E  Size. 

Thickness 

c 

Thickness 
G 

E 

A 

B; 

D 

K 

4X  4 

.40 

.40 

4 

3.16 

11.15 

11.15 

7.16 

6X   6 

.43 

.43 

6 

4.25 

15.50 

15.50 

8.25 

6X  4 

.43 

.40 

4 

4.25 

15.50 

15.25 

8.25 

8X  8 

.46 

.46 

8 

5.31 

19.30 

19.30 

9.31 

8X  6 

.46 

.43 

6 

5.31 

19.30 

19.05 

9.31 

8X  4 

.46 

.40 

4 

5.31 

19.30 

18.80 

9.31 

10X10 

.49 

.49 

10 

6.75 

22.75 

22.75 

10.75 

10X  8 

.49 

.46 

8 

6.75 

22.75 

22.50 

10.75 

10X  6 

.49 

.43 

6 

6.75 

22.75 

22.25 

10.75 

10X  4 

.49 

.40 

4 

6.75 

22.75 

22.00 

10.75 

12X12 

.54 

.54 

12 

7.25 

26.75 

26.75 

11.75 

12X10 

.54 

.49 

10 

7.25 

26.75 

26.75 

11.75 

12X  8 

.54 

.46 

8 

7.25 

26.75 

26.50 

11.75 

12X  6 

.54 

.43 

6 

7.25 

26.75 

26.25 

11.75 

12X  4 

.54 

.40 

4 

7.25 

26.75 

26.00 

11.75 

16X16 

.60 

.60 

16 

9.12 

33.13 

33.13 

13.62 

20X20 

.67 

.67 

20 

11.03 

38.53 

38.53 

15.53 

24X24 

.76 

.76 

24 

13.00 

43.00 

43.00 

18.00 

30X30 

.88 

.88 

30 

13.75 

52.50 

52.50 

18.75 

36X36 

.99 

.99 

36 

18.37 

60.38 

60.38 

23.37 

42X42 

1.10 

1.10 

42 

22.00 

70.00 

70.00 

27.00 

48X48 

1.26 

1.26 

48 

25.00 

80.00 

80.00 

30.00 

MAINS. 


193 


REDUCERS. 


Thickness 

Thickness 

Size. 

C 

D 

H 

J 

K 

7 

6X  4 

A3 

.40 

7 

2.5 

2.5 

12.0 

8X   6 

.46 

.43 

7 

2.5 

2.5 

12.0 

8X   4 

.46 

.40 

15 

2.5 

2.5 

20.0 

10X  8 

.49 

.46 

7 

2.5 

2.5 

12.0 

10X  6 

.49 

.43 

15 

2.5 

2.5 

20.0 

10X  4 

.49 

.40 

23 

2.5 

2.5 

28.0 

12X10 

.54 

.49 

7 

3.0 

2.5 

12.5 

12X  8 

.54 

.46 

15 

3.0 

2.5 

20.5 

12X  6 

.54 

.43 

23 

3.0 

2.5 

28.5 

16X12 

.60 

.54 

15 

2.5 

2.5 

20.0 

16X10 

.60 

.49 

24 

3.0 

2.5 

29.5 

16X  8 

.60 

.46 

32 

3.0 

2.5 

37.5 

20X16 

.67 

.60 

16 

2.5 

2.5 

21.0 

20X12 

.67 

.54 

32 

2.5 

2.5 

37.0 

20X10 

.67 

.49 

40 

3.0 

2.5 

45.5 

24X20 

.76 

.67 

14.5 

3.5 

3.0 

21.0 

24X16 

.76 

.60 

30.5 

3.5 

3.0 

37.0 

30X24 

.88 

.76 

24.0 

3.0 

3.0 

30.0 

30X20 

.88 

.67 

39.0 

3.5 

3.0 

45.5 

36X30 

.99 

.88 

24.0 

3.0 

3.0 

30.0 

36X24 

.99 

.76 

48.0 

3.0 

3.0 

54.0 

42X36 

1.10 

.99 

24.0 

3.0 

3.0 

30.0 

42X30 

1.10 

.88 

48.0 

3.0 

3.0 

54.0 

48X42 

1.26 

1.10 

24.0 

3.0 

3.0 

30.0 

48X36 

1.26 

.99 

48.0 

3.0 

3.0 

54.0 

194 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


HOLDER   DRIPS. 


Size. 

Thickness  of 
Metal. 

A 

O 

H 

C 

4 

.57 

14 

49.00 

54 

4 

6 

.57 

14 

47.00 

54 

6 

8 

.64 

18 

45.00 

54 

8 

10 

.64 

18 

43.00 

54 

10 

12 

.76 

24 

46.81 

60 

12 

16 

.88 

30 

54.75 

72 

16 

20 

.88 

30 

50.56 

72 

20 

24 

.88 

30 

46.38 

72 

24 

30 

.99 

36 

51.38 

84 

30 

36 

1.10 

42 

45.38 

84 

36 

42 

1.26 

48 

45.38 

90 

42 

48 

1.35 

54 

39.25 

90 

48 

YARD  DRIPS. 


Size. 

Thickness  of 
Metal. 

A 

O 

H 

C 

4 

.57 

14 

49.00 

54 

4 

6 

.57 

14 

47.00 

54 

6 

8 

.64 

18 

45.00 

54 

8 

10 

.64 

18 

43.00 

54 

10 

12 

.76 

24 

46.81 

60 

12 

16 

.88 

30 

54.75 

72 

16 

20 

.88 

30 

50.56 

72 

20 

24 

.88 

30 

46.38 

72 

24 

30 

.99 

36 

51.38 

84 

30 

36 

1.10 

42 

45.38 

84 

36 

42 

1.26 

48 

45.38 

90 

42 

48 

1.35 

54 

39.25 

90 

48 

MAINS. 


195 


LINE  DRIPS. 


Size. 

Thickness  of 
Metal. 

A 

O 

H 

C 

4 

.54 

12 

13.00 

18 

4 

6 

.54 

12 

21.00 

28 

6 

8 

.54 

12 

23.00 

32 

8 

10 

.60 

16 

25.00 

36 

10 

12 

.60 

16 

26.81 

40 

12 

16 

.67 

20 

26.75 

44 

16 

20 

.76 

24 

26.56 

48 

20 

24 

.88 

30 

26.38 

52 

24 

30 

.99 

36 

25.38 

58 

30 

36 

1.10 

42 

25.38 

64 

36 

42 

1.26 

48 

25.38 

70 

42 

48 

1.35 

54 

25.25 

76 

48 

ONE-SIXTEENTH  BEND. 


Size. 

Thickness. 

A 

C 

R 

4 

.40 

2.67 

20.25 

6 

6 

.43 

3.50 

20.76 

9 

8 

.46 

4.34 

21.25 

12 

10 

.49 

5.17 

22.00 

15 

12 

.54 

5.76 

22.50 

18 

16 

.60 

7.18 

23.75 

24 

20 

.67 

8.60 

24.75 

30 

24 

.76 

10.02 

26.00 

36 

30 

.88 

12.02 

27.75 

45 

OF   THE 

UNIVERSITY 


196 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


ONE-SIXTEENTH  BEND. 


Size. 

Thickness. 

A 

B 

R 

4 

.40 

14.70 

2.69 

6 

6 

.43 

15.53 

3.53 

9 

8 

.46 

16.38 

4.38 

12 

10 

.49 

17.25 

5.22 

15 

12 

.54 

17.81 

5.81 

18 

ONE-SIXTEENTH   BEND. 


Size. 

Thickness. 

K 

R 

20 

.67 

37.50 

96 

24 

.76 

46.80 

120 

30 

.88 

46.80 

120 

36 

.99 

70.20 

180 

42 

1.10 

70.20 

180 

48 

1.26 

70.20 

180 

MAINS. 


197 


REDUCERS. 


Size. 

Thick- 
ness 
C 

Thick- 
ness 
D 

H 

J 

K 

/ 

M 

K 

/ 

4X   3 

.40 

.40 

7.0 

2.5 

2.5 

12.0 

6.5 

6.5 

16.0 

6X   4 

.43 

.40 

7.0 

2.5 

2.5 

12.0 

6.5 

6.5 

16.0 

6X   3 

.43 

.40 

12.0 

2.5 

2.5 

17.0 

6.5 

6.5 

21.0 

8X   6 

.46 

.43 

7.0 

2.5 

2.5 

12.0 

6.5 

6.5 

16.0 

8X   4 

.46 

.40 

15.0 

2.5 

2.5 

20.0 

6.5 

6.5 

24.0 

10X   8 

.49 

.46 

7.0 

2.5 

2.5 

12.0 

6.5 

6.5 

16.0 

10  X   6 

.49 

.43 

15.0 

2.5 

2.5 

20.0 

6.5 

6.5 

24.0 

10X  4 

.49 

.40 

23.0 

2.5 

2.5 

28.0 

6.5 

6.5 

32.0 

12X10 

.54 

.49 

7.0 

3.0 

2.5 

12.5 

7.0 

7.0 

17.0 

12  X   8 

.54 

.46 

15.0 

3.0 

2.5 

20.5 

7.0 

7.0 

25.0 

12X   6 

.54 

.43 

23.0 

3.0 

2.5 

28.5 

7.0 

7.0 

33.0 

16X12 

.60 

.54 

15.0 

2.5 

2.5 

20.0 

7.0 

7.0 

24.5 

16X10 

.60 

.49 

24.0 

3.0 

2.5 

29.5 

7.0 

7.0 

34.0 

16X   8 

.60 

.46 

32.0 

3.0 

2.5 

37.5 

7.0 

7.0 

42.0 

20X16 

.67 

.60 

16.0 

2.5 

2.5 

21.0 

7.0 

7.0 

25.5 

20X12 

.67 

.54 

32.0 

2.5 

2.5 

37.0 

7.0 

7.0 

41.5 

20X10 

.67 

.49 

40.0 

3.0 

2.5 

45.5 

7.0 

7.0 

50.0 

24X20 

.76 

.67 

14.5 

3.5 

3.0 

21.0 

8.0 

8.0 

26.0 

24X16 

.76 

.60 

30.5 

3.5 

3.0 

37.0 

8.0 

8.0 

42.0 

30X24 

.88 

.76 

24.0 

3.0 

3.0 

30.0 

8.0 

8.0 

35.0 

30X20 

.88 

.67 

39.0 

3.5 

3.0 

45.5 

8.0 

8.0 

50.5 

36X30 

.99 

.88 

24.0 

3.0 

3.0 

30.0 

8.0 

8.0 

35.0 

36X24 

.99 

.76 

48.0 

3.0 

3.0 

54.0 

8.0 

8.0 

59.0 

42X36 

1.10 

.99 

24.0 

3.0 

3.0 

30.0 

8.0 

8.0 

35.0 

42X30 

1.10 

.88 

48.0 

3.0 

3.0 

54.0 

8.0 

8.0 

59.0 

48X42 

1.26 

1.10 

24.0 

3.0 

3.0 

30.0 

8.0 

8.0 

35.0 

48X36 

1.26 

.99 

48.0 

3.0 

3.0 

54.0 

8.0 

8.0 

59.0 

198 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


FLANGES. 


3 

a 

*Ji 

g  ij 

Distance 
A 

I 
1* 

|* 

Outside 
Diam. 

Finished 
Thick- 
ness. 

P* 

4 

oK 

ID 
rf"o 

-S« 

02 

a? 

t 

1 

4X   4 

.40 

6 

6 

7 

9 

.72 

7  .  125 

4 

1 

2 

1X2* 

6X  6 

.43 

8 

8 

8 

11 

.77 

9.125 

4 

! 

3 

IX2J 

6X   4 

43-40 

8 

8 

8 

8X   8 

.46 

10 

10 

9.25 

13.5 

.81 

11.125 

8 

1 

3 

IX2J 

8X  6 

46-43 

10 

10 

10X10 

.49 

11 

11 

10.50 

16 

.86 

13.75 

8 

1 

4 

1X2} 

10X  8 

49-46 

11 

11 

10X  6 

49-43 

11 

11 

12X12 

.54 

12 

12 

11.0 

19 

.93 

15.75 

8 

! 

4 

IX2J 

12X10 

54-49 

12 

12 

12  X  8 

54-46 

12 

12 

16X16 

.60 

14 

14 

15.25 

22.5 

1.0 

20.0 

12 

1 

4 

1X3- 

16X12 

6-54 

14 

14 

16X10 

6-49 

14 

14 

20X20 

.67 

18 

18 

16.75 

27 

1.0 

24.5 

16 

i 

5 

|X3 

20X16 

67-6 

18 

18 

20X12 

67-54 

38 

18 

24X24 

.76 

20 

20 

18.75 

31 

1.125 

28.5 

16 

i 

5 

JX4 

24X20 

76-67 

20 

20 

24X16 

76-60 

20 

20 

30X30 

.88 

24 

24 

22 

37.5 

1.25 

35.0 

20 

i 

5 

1X4 

30X24 

88-76 

24 

24 

30X20 

88-67 

24 

24 

36X36 

.99 

29 

29 

25.5 

44 

1.375 

41.25 

24 

i 

5.5 

1X4 

36X30 

99-88 

29 

29 

36X24 

99-76 

29 

29 

42X42 

1.10 

32 

32 

29 

50.75 

1.56 

47.75 

28 

if 

5.5 

1X4 

42X36 

1.1-99 

32 

32 

42X30 

1.1-88 

32 

32 

48X48 

1.26 

35 

35 

33 

57 

1.75 

54.0 

32 

li 

5.5 

1X4 

48X42 

1.26-1.1 

35 

35 

48X36 

1.26^99 

35 

35 

MAINS. 


190 


STANDARD   STRAIGHT    PIPE. 


Size. 

Thick- 
ness. 

Ext. 
Diam. 

Diam., 
Socket. 

Depth, 
Socket. 

A 

B 

C 

L 

Weight, 
Foot. 

Weight, 
Length. 

4 

.40 

4.80 

5.80 

4.00 

.50 

.30 

.65 

0.50 

19.0 

228 

6 

.43 

6.90 

7.90 

4.00 

.50 

.40 

.70 

0.50 

30.0 

360 

8 

.46 

9.05 

10.05 

4.00 

.50 

.50 

.75 

0.50 

42.0 

504 

10 

.49 

11.10 

12.10 

4.00 

.50 

.50 

.75 

0.50 

55.8 

670 

12 

.54 

13.20 

14.20 

4.50 

.50 

.60 

.80 

0.50 

72.5 

870 

16 

.60 

17.20 

18.30 

4.50 

.75 

.80 

.90 

.55 

108.3 

1300 

20 

.67 

21.34 

22.59 

4.50 

1.75 

2.00 

1.00 

.625 

150.0 

1800 

24 

.76 

25.52 

26.77 

5.00 

2.00 

2.10 

1.05 

.625 

204.2 

2450 

30 

.88 

31.74 

32.99 

5.00 

2.00 

2.30 

1.15 

.625 

291.7 

3500 

36 

.99 

17.96 

39.21 

5.00 

2.00 

2.50 

1.25 

.625 

391.7 

4700 

42 

1.10 

44.20 

45.45 

5.00 

2.00 

2.80 

1.40 

.625 

512.5 

6150 

48 

1.26 

50.50 

51.75 

5.00 

2.00 

3.00 

1.50 

.625 

666.7 

8000 

CHAPTER  XIV. 
SERVICES. 

Sizes. —  Services  for  an  ordinary  dwelling  within  40  ft.  of  a 
street-main  should  never  be  smaller  than  1  in.;  but  it  is  better 
practice  to  run  services  not  smaller  than  1^-in.  pipe.  The  very 
small  increase  in  cost  of  service  is  vastly  offset  by  the  saving  in 
efficiency  and  attention  required  to  maintain  it  in  proper  condition, 
for,  aside  from  its  actual  capacity  for  transmitting  gas,  a  small 
amount  of  water,  naphthalene,  or  other  deposit  which  would 
hardly  be  noticed  in  a  IJ-in.  pipe  would  seriously  affect  the  flow 
of  gas  through  a  j-in.  pipe.  For  large  buildings,  an  estimate  of 
its  consumption  capacity  should  be  made,  and  a  calculation  made 
from  that  as  to  the  size  of  pipe  suitable,  the  calculation  being 
made  either  by  consulting  a  table  or  working  out  the  problem  by 
the  regular  formula  for  the  flow  of  gases. 

When  service-cocks  are  used  at  the  curb,  they  should  be  in- 
spected at  least  once  a  year,  to  see  that  they  are  in  good  working 
order  and  that  the  stop-boxes  are  clean,  and  the  cocks  easily  accessi- 
ble. All  services  should  have  these  curb-boxes,  and  where  such 
have  been  omitted  they  should  be  cut  in,  as  they  are  of  vital  im- 
portance in  case  of  fire  and  other  discontinuance  of  service. 

Tapping. — Leaks  in  piping  are  most  readily  located  by  the 
introduction  into  the  pipe  of  essence  of  peppermint,  wintergreen, 
ether,  or  pennyroyal  with  an  air-pump.  This  essence  is  dissem- 
inated by  air  pressure  through  the  pipe  system.  The  general 
locality  of  the  leak  being  indicated  by  the  escaping  odor,  which 
may  be  more  immediately  localized  by  the  use  of  heavy  soap-suds 
put  on  with  a  camel's-hair  brush,  the  escaping  air  being  indicated 
by  numerous  fine  bubbles. 

Generally  in  making  the  tap  it  should  be  made  in  the  upper 
side  of  the  main,  using  a  street  L,  or  better  still  a  street  T,  with 
a  plug  for  making  the  connections,  the  connections  being  thoroughly 
white-  or  red-leaded. 

It  should  be  borne  in  mind  not  to  tap  too  large  a  service  directly 

200 


SERVICES.  201 

into  too  small  a  main.  The  largest  service  permissible  for  tapping 
direct  into  a  main  is  as  follows: 

In  a  3-in.  main,  a  1-in.    service-tap. 
"  "  4-in.     "       "  IJ-in.  " 

"  "  6-in.     "       "  l|-in. 

In  attaching  a  1-in.  service-tap  to  a  3-in.  main  it  is  well  to  tap 
the  main  only  f  in.,  using  an  increaser  or  reducer.  In  case,  how- 
ever, it  is  necessary  to  connect  larger  services  with  the  main,  two 
or  more  taps  may  be  made  (staggered)  and  connected  into  a 
header,  or  a  split-sleeve  may  be  used  and  the  connection  made 
into  it.  It  is  a  rule  with  many  gas  companies  to  make  the  tap 
for  all  instances  one  size  less  than  the  size  of  the  service  to  be  run. 
Where  a  split  sleeve  is  used  a  hole  corresponding  with  the  size 
of  the  service  is  tapped  concentrically  with  a  smaller  hole  in  the 
main  over  which  it  is  clamped. 

Small  gas  companies,  from  reasons  of  economy,  frequently  omit 
service-  or  curb-cocks  on  services  under  2  in.  The  use  of  this  cock 
is,  however,  better  practice. 

Coating. — The  question  as  to  whether  or  not  wrought-iron 
service-pipes  should  be  coated  depends  largely  upon  the  character 
of  soil  through  which  they  run.  It  is  certain,  however,  that  in  the 
neighborhood  •  of  ice-cream  saloons,  fish-markets,  and  localities 
where  the  pipe  must  be  exposed  through  areaways,  etc.,  galvanized 
iron  should  be  used.  The  following  is  a  recipe  for  pipe-coating 
used  by  one  of  the  large  western  gas  companies  and  which  can  be 
recommended  by  the  writer: 

"  Bring  a  kettle  of  tar  (20-gallon)  to  a  low  boiling-point  and 
add  20  pounds  of  fresh-slaked  lime,  sifted  over  the  top  and  worked 
down.  Boil  down  to  a  paste  or  a  consistency  about  midway  between 
tar  and  pitch.  Let  it  settle  for  a  few  minutes,  then  add  4  pounds  of 
tallow  and  1  pound  of  powdered  rosin,  stir  until  they  are  thoroughly 
dissolved  and  incorporated  with  the  tar,  then  let  it  cool  and  settle. 
Ladle  off  into  barrels.  When  ready  for  use,  to  each  barrel  of  45 
gallons  of  the  above  mixture  add  4  pounds  of  crude  rubber  dis- 
solved in  turpentine  to  the  consistency  of  thick  cream.  Heat  the 
mixture  to  about  100  deg.  Fahr.  and  immerse  the  service-pipe, 
heated  to  about  the  same  temperature." 

A  V-shaped  trough  will  be  found  convenient  for  dipping  these 
pipes,  although  it  is  better  to  apply  the  mixture  with  a  heavy 
brush,  unless  the  ends  of  the  pipe  are  capped,  as  the  mixture 
should  be  excluded  from  the  interior  of  the  pipe.  In  makinp  joints 
care  should  be  taken  to  see  that  the  threads  of  the  service  are 
free  from  coating. 


202  AMERICAN  GAS-ENGINEERING   PRACTICE. 

Proper  cards  should  be  made  out  for  all  services  and  should  be 
indexed  and  filed.  These  cards  should  form  a  perpetual  record, 
beginning  at  the  installation  of  the  service,  showing  location,  di- 
mensions, cost,  etc.,  to  which  should  be  added  notes  of  all  repairs, 
renewals,  extensions,  and  further  work. 

In  connecting  old  services  with  new  mains,  as  is  the  case  where 
larger  mains  are  run  to  take  the  place  of  old  ones,  the  usual  prac- 
tice is  to  make  the  final  or  connection  joint  with  such  service,  one 
which  can  be  made  without  turning  either  of  the  runs  of  the  pipe, 
which  are  connected  together.  There  are  several  such  joints  made 
and  used  with  wrought-iron  or  steel  pipe,  the  most  convenient 
being  what  are  known  as  long-screws  or  running  threads,  of  which 
the  last  named  are  generally  the  best,  although  under  some  condi- 
tions flanged  joints  or  " unions"  may  be  used.  Care  should  be 
taken  where  services  drip  or  slope  back  toward  the  main  that  this 
drip  be  not  affected  by  the  increased  diameter  of  the  main. 

Freezing. — In  putting  in  gas-piping  that  will  be  exposed  to 
extreme  cold,  such  as  the  risers  of  street-lamps,  mains  crossing 
bridges,  and  services  entering  houses,  obstructions  in  pipes  from 
frost  may  be  prevented,  either  by  enlarging  the  portion  of  the 
pipe  in  which  the  frost  tends  to  accumulate  to  a  sufficient  extent 
to  permit  the  passage  of  gas  of  an  adequate  amount,  after  the  frost 
has  accumulated  on  the  interior  sides  of  the  pipe  to  a  thickness 
sufficient  to  form  a  non-conductor  of  heat  and  thereby  preventing 
further  formation,  or  by  covering  the  pipe  with  some  non-conductor 
which  prevents  the  reduction  of  the  passing  gas  to  a  frost  tempera- 
ture. The  first  arrangement  is  perhaps  preferable,  the  enlarge- 
ment of  pipes  to  about  two  sizes  larger  generally  being  found 
sufficient.  It  is  necessary  sometimes  when  the  size  of  the  pipe,  as 
in  the  case  of  16-  to  20-in.  mains,  would  render  this  impracticable, 
to  place  hand-holes,  T's,  or  cleanouts  in  such  locations  as  may  be 
convenient  for  removing  such  stoppage  after  its  formation. 

Attention  has  been  called  to  the  removal  of  burrs,  left  by  roller- 
cutters,  from  the  interior  of  pipe.  This  is  extremely  important, 
and  all  wrought-iron  pipe  after  being  cut  should  invariably  be 
renewed,  as  such  burrs  not  only  materially  reduce  the  capacity  of 
the  pipe,  but  form  a  trap  and  bearing  for  the  accumulation  of  all 
manner  of  stoppage.  A  practical  fitter  who  has  given  the  matter 
careful  study  has  proved  by  actual  measurement  that  in  smaller 
pipes,  f-in.  to  2-in.,  these  burrs  will  reduce  the  area  all  the  way 
from  3.1  to  30.4  per  cent.,  with  an  average  reduction  in  the  range 
of  sizes  of  15.25  per  cent.  Many  theoretically  good  steam  and  hot- 
water  jobs  fail  of  practical  results  from  no  other  reason  than  that 
the  fitter  neglected  to  remove  the  burrs  from  the  pipe.  Not  only 
does  the  collection  of  sediment  about  the  burrs  choke  up  the  pipe, 


SERVICES. 


203 


but  they  arrest  the  flow  of  water,  causing  it  to  stagnate  and  cor- 
rode the  pipe  at  the  joints.  Gas-service  pipes  are  small  in  diameter, 
and  burrs  left  by  cutting-wheels  reduce  the  area  from  16  to  30  per 
cent.  To  maintain  effective  pressure  it  is  almost  imperative  that 
these  pipes  be  reamed. 

Forcing=jacks. — The  Barrett  horizontal  jack  may  be  used  to 
considerable  advantage  for  forcing  pipe  through  earth  in  place  of 
digging  a  trench  for  short  distances  in  sandy  or  clayey  soils  which 
are  free  from  stone  or  other  obstruction.  They  may  also  be  used 
in  forcing  pipe  under  sidewalks  and  for  short  distances  where  tun- 


FIG.  42. — Scotch  Yoke  for  By-passing  Obstructions  when  Laying  Services. 

neling  is  inconvenient.  For  a  long  run,  however,  this  practice  is 
dangerous,  there  being  an  opportunity  for  the  pipe  to  kink,  buckle, 
or  trap,  or  at  least  not  to  maintain  its  proper  gradient. 

At  the  meeting  of  the  International  Society  for  Testing  Materials 
in  1900  Professor  Howe  gave  further  data  from  some  large-scale 
experiments  conducted  by  himself,  in  which  he  exposed  a  number 
of  plates  of  wrought  iron,  soft  steel,  and  nickel  steel  J  inch  thick  to 
the  action  of  sea-water,  river-water,  and  the  weather  for  two  periods 
of  one  year  each.  The  results  are  summed  up  as  follows: 


\VTroufirht  iron 

Sea-water. 
100 

Fresh  water.  Weather. 
100                 100 

94             103 
80               67 
32               30 

Average. 
100 

103 
77 
31 

Soft  steel 

.  .   114 

3  per  cent  nickel  steel     .  . 

83 

25  per  cent,  nickel  steel.  . 

.    32 

Professor  R.  H.  Thurston,  from  his  tests  and  observation  of 
these  materials  in  practice,  concludes  on  the  whole  that  steel  resists 
corrosion  better  than  iron. 

Fittings. — The  greatly  increased  use  of  high-pressure  gas  sys- 
tems throughout  the  country  has  made  necessary  the  use  of  special 
fittings,  especially  for  service  connections,  with  wrought-iron  and 


204 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


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SERVICES. 


205 


206 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


steel  pipe.     These  connections  are  special  patterns  and  are  usually 
tested  under  150  Ibs.  of  air  pressure. 

The  clamps  are  especially  galvanized,  and  the  fittings  made  of 


FIG.  45. — High-pressure  Cocks  Connected  in  Service -clamps. 

material  and  composition  adapted  to  this  class  of  work,  the  keys 
having  greater  lap  and  the  bodies  being  carefully  ground  and  oil- 
polished. 

Fig.  45  shows  a  number  of  these  connections,  they  being  made 
preferably  with  a  swing- joint.  A  wooden  plug  is  shown  inserted  in 
the  hole  in  the  main  through  the  fittings  which  prevents  the  escape 
of  gas  while  the  service  is  being  completed,  after  which  it  can  be 
removed  and  the  fittings  permanently  plugged. 

Should  it  become  necessary  at  any  time  to  remove  the  service- 
clamp  from  the  main,  a  wooden  plug  may  be  again  inserted  and 
the  clamp  removed  without  further  escape  of  gas. 

Fig.  43  indicates  a  number  of  .fittings  used  in  this  connection, 


FIG.  46.— Types  of  Mueller  Century  Service- clamp. 

especially  manufactured  for  the  purpose,  and  Fig.  49  indicates  the 
Mueller  High-pressure  Gas-main  Drilling-machine,  operating  Ion  • 
boring-bars,  so  that  the  hole  in  the  main  may  be  drilled  through 
either  the  clamps  illustrated  in  Figs.  46  and  47,  or  through  any  of 
the  fittings  of  Fig.  43. 

This  is  of  especial  advantage  where  exceedingly  high  pressure 


SERVICES. 


207 


is  used,  it  being  good  practice  to  use  gas-service  cocks  in  connec- 
tion with  the  clamps  and  tees,  both  to  prevent  the  escape  of  gas 


FIG.  47. — Combined  High-pressure 
Clamp  and  Service  Tee. 


FIG.  48.— Lead  Gasket  Filling  under 
Saddle  of  Service-clamp. 


and  to  enable  at  all  times  uninterrupted  access  in  the  construction 
or  maintenance  of  the  service. 

The  writer  believes  that  the  double  clamp,  illustrated  in  Fig. 


FIG.  49. — Mueller  High-pressure  Tapping-machine. 

46,  in  connection  with  the  swing-joint  and  service-cock,  illustrated 
in  Fig.  45,  is  the  ideal  high-pressure  connection. 

Where  services  are  to  be  subjected  to  pressure  of  over  20  Ibs., 
extra-heavy  wrought-iron  pipe  or  steel  pipe,  together  with  extra- 
heavy  fittings,  should  be  used.  This  is  not  so  much  by  reason  of 
its  safe  working-pressure  as  by  the  saving  in  leakage  and  rigidity 
attained. 


208 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


FIG.  50. — General  Scheme  for  High-pressure  Service  Connection. 

High-pressure  Service  Connections. — The  scheme  of  arrangement  fop 
connecting  a  high-pressure  system,  as  illustrated  in  the  above  diagram,  Fig. 
50,  working  from  right  to  left,  is  as  follows:    On  the  gas  main,  which  is  pre- 
sumed to  be  a  steel,  wrought-iron,  cast-iron,  or  Universal  pipe,  the  yoke  service 
clamp  with  proper  lead  gaskets  is  attached  and  tightly  clamped.     The  main 
being  tapped  through  the  orifice  of  the  yoke,  a  high-pressure  main  cock  is 
inserted,  into  which  in  turn  is  inserted  a  service  tee  having  one  end  plugged, 
and  a  service  ell  screwed  into  its  side  port.     Into  this  ell  the  service  pipe  is 
screwed  and  the  run  of  the  service  taken  up  to  the  curb,  where  a  curb  cock, 
protected  by  a  proper  service  box,  is  intersected.     Continuing  the  run  of  the 
service,  it  enters  the  building,  and  immediately  inside  the  wall  a  high-pressure 
female  lock-wing  meter  cock  is  interposed,  from  whence  the  service  continues 
to  a  tee,  one  side  having  a  plug  or  pet  cock  for  dripping  purposes,  and  into  the 
other  a  riser,  which  proceeds  to  the  inlet  of  the  regulator.     This  regulator  is  of 
the  opposed  diaphragm  balance-valve  type  with  a  by-pass  connecting  its  shell 
with  the  safety  vent  pipe,  in  case  of  breakage  to  the  diaphragm  of  possible 
leakage.     From  the  outlet  of  the  regulator  the  riser  is  connected  with  a  by- 
pass upon  which  is  placed  a  mercury  seal,  which  is  so  designed  that  in  case  of 
"  blowing  the  seal"  the  mercury  will  overflow  into  a  receiving  trough  and 
by-pass  the  gas  supply  to  the  safety   air-vent  until  replaced  into  its  cup. 
The  function  of  the  seal  is  to  act  as  an  additional  safety  valve  and  should 
have  a  resistance  only  slightly  above  the  maximum  pressure  required  at 
the  outlet  of  the  meter,  in  order  that  in  case  of  accident  occurring  to  the 
proper  working  of  the  regulator  the  seal  will  blow  and  the  gas  escape  through 
the  fresh-air  vent  operating  the  alarm  whistle,1  rather  than  forcing  its  way  all 
through  the  meter  and  into  the  house  pipe  and  fixtures.     The  fresh-air  vent 
should  be  carried  to  a  considerable  height  and  should  not  be  immediately 
adjacent  to  any  window,  flue,  or  other  orifice  in  the  wall.     From  the  mercury- 
seal  by-pass  the  gas  passes  through  a  regular  goose-neck  meter  connection 
he  meter  and  from  thence  into  the  main  riser  of  the  house  pipe, 


CHAPTER  XV. 
CONSUMERS'  METERS. 

Testing. — All  meters,  when  received  from  the  factory,  should  be 
proved  before  being  placed  in  service.  The  rating  of  consumers' 
meters,  as  to  capacity,  is  three  times  its  rated  capacity  of  6  cu.  ft. 
of  gas  consumption  per  burner-hour;  thus  we  have  in  a  three-light 
meter  about  3X3X6  =  54  cu.  ft.  per  hour.  In  addition  to  the  orig- 
inal test  and  such  test  as  may  be  occasioned  through  complaints 
and  contested  bills,  each  meter  should  be  tested  whenever  removed 
and  brought  to  the  shop  and  a  record  concerning  such  test  be  duly 
filed.  Periodically  these  files  should  be  gone  over  numerically  and 
all  meters  which  have  not  been  tested  within  a  period  of  3  years 
should  be  brought  to  the  shop  and  duly  proved.  It  is  good  prac- 
tice to  permit  a  meter  to  remain  in  the  shops  at  least  12  hours 
before  proving,  in  order  that  there  may  be  an  equalization  of  tem- 
perature. 

All  meters  showing  a  deviation  by  the  prover-test  of  2  per  cent., 
either  fast  or  slow,  should  be  corrected  or  returned  to  the  factory 
for  repairs.  Test  each  meter  with  gas  to  see  that  it  registers  with 
a  very  small  consumption  (called  "check-test");  using  a  flame  not 
larger  than  a  dime,  after  which  turn  off  the  flame,  leaving  gas- 
pressure  on  meter;  this  is  for  detecting  any  holes  in  the  dia- 
phragm or  a  leak  in  the  valve.  Then  test  for  sticking  or  irregularity 
of  flow  by  turning  the  gas  on  stronger  until  the  flame  should  show 
two  small  horns.  The  best  way  to  make  this  test  is  to  have  burners 
connected  up  on  a  header  or  stand  of  burners  with  sufficiently 
numerous  outlets  to  work  the  meter  to  its  full  capacity. 

The  third  test  is  the  regular  one  on  the  prover.  When  tests  are 
made  with  the  cover  on  the  meter  they  should  be  for  not  less  than 
two  revolutions  of  the  test-hand.  When  the  cover  is  off  a  satis- 
factory test  can  be  made  with  one  revolution,  this  being  made  by 
both  the  "open"  and  "check"  test.  Meters  showing  a  variance 
within  4  per  cent,  can  generally  be  regulated  in  the  shop,  but  for 
more  than  that  amount  it  is  good  practice  to  return  them  to  the 
factory. 

209 


210 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


In  making  the  prover-test  care  should  be  taken  that  the  water 
in  the  prover  and  the  air  in  the  room  are  at  an  identical  tempera- 
ture. Make  sure  that  the  connections  of  the  prover  are  perfectly 
tight,  and  then  allow  a  cubic  foot  or  more  of  air  to  pass  through  the 
meter,  stopping  with  the  pointer  on  the  test-dial  exactly  at  a  divi- 
sion mark,  then  carefully  adjust  the  pointer  on  the  holder  to  zero, 
turn  on  the  air  to  the  meter  and  make  one  more  complete  revolu- 
tion of  pointer  on  dial,  stopping  precisely  at  the  point  started  from. 
The  error  corresponding  to  the  discrepancy  between  the  meter  and 
the  prover  can  then  be  calculated. 

Capacities. — The  following  table  is  given  by  the  gas  educational 
trustees  of  the  American  Gaslight  Association  as  the  average 
capacity  of  the  number  of  gas-meters  resulting  from  a  series  of 
tests  of  several  makes: 


CAPACITY  OF  GAS-METERS. 


Size  Meter. 

Capacity  in  Cubic 
Feet  per  Hour  with 
Loss  of  Pressure  of 
&  in. 

Capacity  in  Cubic 
Feet  per  Hour  with 
Loss  of  Pressure  of 
T8o  in. 

3-light 

40 

55 

5-light  
10-light  
20-light  

50 
80 
115 

75 
120 
160 

30-light  

175 

270 

45-light  
60-light  
100-light      .... 

215  • 
330 
385 

315 
475 
600 

150-li?ht  
300-light  

1015 
1635 

It  is  important  that  all  consumers'  meters  not  in  use  should  be 
carefully  corked  so  as  to  make  them  air-tight  in  order  to  prevent 
the  drying  of  the  diaphragms.  These  corks  should  also  remain  in 
when  the  meters  are  shipped  to  the  repair  shops.  Every  consumer's 
meter,  when  set,  should  be  carefully  supported  in  position  by  a 
bracket,  and  in  no  case  should  it  be  allowed  to  hang  on  its  own 
connections. 

Meters  should  be  badged  immediately  when  purchased  and 
their  identity  established  by  recording  them  in  a  meter-record  book 
or  card  system  with  index.  This  is  of  the  utmost  importance.  In 
the  case  of  a  condemned  meter,  or  one  otherwise  destroyed,  a  proper 
note  should  be  made,  embracing  all  details  upon  this  register. 

In  shipping  meters  back  to  the  repair  shop  an  invoice  should  be 
inclosed  giving  description  of  each  meter  and  the  reading  of  the 


CONSUMERS'  METERS. 


211 


index.  The  returns  made  by  the  repair  shop  should  be  carefully 
preserved.  Every  meter  should  thus  be  accounted  for  either  as 
set  (as  shown  by  route  book  and  consumer's  ledger),  in  stock,  sent 
away  for  repairs,  destroyed,  or  condemned.  With  the  meter- 
badges  on  hand  this  should  account  for  the  whole  number  of  badges. 
As  a  general  rule  all  meters  not  being  used  should  be  removed  and 
put  in  stock. 

Meter  Connections. — Meter  connections  should  be  made  of  uni- 
form length  so  that  they  will  be  interchangeable.  They  should  not 
be  too  short,  as  they  are  then  hard  to  bend  without  buckling.  A 
good  length  for  the  smaller  sizes  is  12  in.  and  for  the  larger  sizes 
14  in.,  16  in.,  and  18  in.  When  a  meter  is  removed  for  an  indefi- 
nite period  the  lead  connections  and  cock  should  be  removed  and 
the  service  and  riser  capped  or  plugged.  Meter  connections  should 
be  made  as  follows: 

SIZE  OF  METER  CONNECTIONS. 


Diameter  of 

Diameter  of 

Diameter  of 

Siae  Meter. 

Iron  Pipe. 

Cock. 

Lead  Pipe. 

Inch. 

Inch. 

Inch. 

3-light  

a 

2 

§ 

5-light  

3 

10-light 

1 

1 

1 

Meters  rated  at  30  lights  and  over  should  be  provided  with 
screw  connections  instead  of  lead.     Only  standard  connections 


FIG.  51. — Iron  Meter  Connection. 


should  be  used  and  a  set  of  hard-brass  standard  gages  should  be 
provided  in  every  meter-shop.     All  new  meters  and  unions  should 


212 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


immediately  upon  receipt  from  the  factory  be  tested  with  these 
gages,  and  failing  in  standard  should  be  rejected. 

The  gage  consists  of  two  parts,  a  screw  and  a  nut.  The  threads 
of  the  screw  are  exactly  standard ;  the  countersink  in  the  end  of  the 
screw  is  the  diameter  of  the  nose  of  the  swivel.  The  nut  is  made 
to  fit  the  standard  screw  exactly,  and  the  hole  in  it  is  a  gage  for 
the  swivel.  The  standard  dimensions  of  unions  for  3-,  5-,  and  10- 
light  meters  are  as  follows: 

METER  UNION  STANDARDS. 


3-light. 

5-light. 

10-light. 

Number  of  threads  per  inch  

18 

12 

11* 

Diameter  of  screw  inch 

18 

1|3 

lt        "  swivel  or  nipple  inch 

5| 

1* 

tl        ll  nose  of  swivel  inch     

II 

1? 

Frost  and  naphthalene  can  be  removed  from  meters  by  pouring 
in  the  inlet  a  small  quantity  of  wood  alcohol  or  benzine.  The 
process  of  injecting  alcohol  in 
a  vaporized  condition  into  the 
main,  as  described  elsewhere 
by  the  writer,  has  an  exceed- 
ingly beneficial  effect  upon  the 


meters 


dia- 


FIG.  52. — Test-meter. 


FIG.  53. — Complaint  Meter. 


phra°;m  and  removing  tar,  naphthalene,  and  frost. 

Meter-readers  should  be  prevented  from  using  matches  in  read- 
ing meters;   proper  lanterns  (Davy  safety-lamp  type)  being  sub- 


CONSUMERS'   METERS. 


213 


MM* 

Atldrrts 

^c"7°  METER. 
/"</«.  SMri 


stituted,  by  reason  of  the  danger  of  explosion  and  ignition  from 
leaks.  It  is  also  well  to  reverse  meter- 
takers  upon  their  routes  in  order  that  each 
meter-taker  may  be  familiar  with  the  entire 
system,  and  also  to  prevent  the  putting 
down  of  "fake"  readings,  which  is  a  great 
temptation  to  the  meter -taker  where 
meters  are  placed  in  inconvenient  locali- 
ties. 

Meter  connections,  when  of  lead,  should 
be  made  of  the  following  class  of  lead  pipe : 

f-in.  pipe  for  3-light  meters,  1£  Ibs.  per 
ft.,  known  as  "C"  pipe. 

j-in.  pipe  for  5-light  meters,  1  j  Ibs.  per 
ft.,  known  as  "C"  pipe. 

1-in.  pipe  for  10-  and  20-light  connec- 
tions, 2  Ibs.  per  ft.,  known  as  UD"  pipe. 

This  pipe  is  to  be  used  when  the  meter 
has  a  sound  support,  but  in  instances 
where  the  connections  are  liable  to  have 


to  carry  all  or  a  large  part  of  the  weight, 
"B"  pipe  should  be  substituted  for  the 
"C"  pipe  in  the  above,  and  "C"  pipe  for 
"D"  pipe.  It  is  much  better  practice, 
however,  to  place  heavy  shelves  or 
brackets  beneath  the  meter,  and  these 
should  be  invariably  required. 

Operation.  —  While  two  -  diaphragm 
meters  have  been  known  to  withstand  a 
gas  pressure  of  18  to  20  in.,  they  should 
under  no  condition  be  subjected  to  such 
a  strain;  the  maximum  should  not  exceed 
5-in.  water-column  pressure  and  the  differ- 
ential or  difference  in  pressure  between 
the  inlet  and  outlet  of  the  consumer's 
meter  should  not  exceed  0.2  of  an  inch. 

The  drop  in  candle  power  after  leav- 
ing the  works,  in  the  case  of  water-gas, 
is  in  some  degree  a  definite  function  of 
atmospheric  temperature  and  barometric 
pressure  and  will,  to  a  certain  extent, 
occur  in  spite  of  the  most  thorough  fixing 
and  careful  condensation. 


FTG.  54. — Record  from 
Complaint  Meter. 


Consumers'  dry-meters  should  never  be  set  so  that  the  con- 
sumer can  readily  twist  it  upside  down,  without  detection,  as  in 


214  AMERICAN  GAS-ENGINEERING  PRACTICE. 

this  case  the  valves  are  apt  to  fall  from  their  seats  and  hang  down, 
thus  permitting  the  free  passage  of  gas  without  registration.  When 
a  consumer's  meter  is  found  inaccurate,  it  is  frequently  the  case 
that  there  is  considerable  difference  between  the  "open"  test  and 
the  " check"  test — the  latter  being  the  test  of  the  meter  under  only 
a  small  portion  of  its  capacity.  The  check  test  is  invariably  the 
most  exacting,  putting  a  severer  requirement  upon  the  meter  and 
thereby  developing  more  fully  the  presence  of  any  internal  leaks. 
Again,  the  time  period  being  longer,  there  is  greater  opportunity  for 
any  lack  of  fitting  on  the  part  of  the  valve,  due  to  dirt  or  wear  or  any 
wear  or  lack  of  adjustment  in  the  tangents,  to  be  manifested. 

In  addition  to  the  regular  consumer's  meter  a  complaint  meter 
is  manufactured  by  the  Maryland  Meter  Co.  It  will  be  found  of 
considerable  use  in  checking  up  complaint  bills,  locating  hour  of 
peak-load  in  certain  buildings,  and  as  a  " tell-tale"  (Fig.  53, 
page  212). 

In  addition  to  this,  every  gas  company  should  be  equipped 
with  one  or  more  wet-  or  test-meters  (Fig.  52),  which  will  be  found 
of  service  in  all  sorts  of  portable  testing,  settlement  of  com- 
plaints, determination  of  leaks,  etc.  Its  minute  subdivision  of 
scale  makes  it  of  great  value  in  this  line. 

Another  reason  for  the  difference  in  registration  in  the  "open" 
and  "check"  test  of  consumer's  meter  is  probably  a  difference  in 
the  distension  of  the  diaphragm-skins  during  the  tests,  the  disten- 
sion generally  being  greater  during  the  open  than  the  check  test. 
This  discrepancy  should  not  vary  over  0.03  per  cent,  either  way; 
it  may  usually  be  corrected  by  softening  the  solder  with  a  hot  iron 
and  moving  the  tangent  slightly  on  its  axis,  the  difference  in 
the  axis  of  the  tangent  compensating  for  this  irregularity  in  the 
skins,  which  difficulty  becomes  more  marked,  as  they  harden  from 
age,  oxidation,  or  condensation. 

Since  the  days  of  Glover,  there  has  been  but  little  change  in 
the  type  and  manufacture  of  the  consumer's  meter.  The  inaccu- 
racies due  to  water  evaporation,  the  corroding  action  of  the  various 
Clements  upon  the  metal  material,  together  with  the  facility  with 
which  the  wet-meter  could  be  "doctored,"  has  practically  put 
that  type  of  meter  out  of  current  use.  There  is  perhaps  no  other 
mechanism  of  its  class  which  has  endured  the  test  of  time  with 
so  little  change  in  its  original  design  as  the  dry-meter,  which  is 
practically  identical  in  construction  as  manufactured  both  in  this 
country  and  abroad. 

The  most  radical  departure  from  the  orthodox  standard  in  this 
line  has  been  made  by  the  H.  H.  Sprague  Co.  of  Bridgeport,  Conn., 
whose  meter  has  now  stood  the  test  of  service  for  some  three 
years.  The  Sprague  Co.  furnish  nipples  and  unions,  which  make 


CONSUMERS'   METERS. 


215 


their  meters  adaptable  to  any  class  of  standard  connections,  thereby 
making  them  interchangeable  with  the  older  types.  Their  No.  1 
meter  has  the  capacity  of  the  3-,  5-, 
and  10-light,  old  style,  while  the  No.  2 
is  equal  to  the  former  30-light;  other 
sizes  are  now  in  process  of  design. 

Meter=testing  Corrections. — In 
using  a  small  gas-holder  or  prover  it 
is  often  found  that  the  temperature 
of  the  gas  passing  through  the  meter 
is  greater  or  less  than  that  found  in 
the  holder,  and  this  may  make  some 
difference  where  accurate  work  is  de- 
sired. For  example,  the  following 
table  shows  the  percentage  increase 
in  volume  of  gas  at  various  tem- 
peratures over  that  at  freezing;  it 

was  compiled  from  English  figures.  ^^ 

Hence,  for  ordinary  purposes  and  FlG.  55._The  Sprague  Meter  of 
ordinary  temperatures,  corrections  Bridgeport,  Conn, 

may  be  made  on  the  assumption  that 

4°  Fahr.  increase  or  decrease  in  the  temperature  of  air  or  gas 
produces  1  per  cent,  variation  in  the  volume  of  such  air  or  gas, 
or  1°  produces  a  difference  of  0.0025  per  cent. 


Temperature  in 
Fahrenheit'  s 

Percentage 
of 

Temperature 
in  Fahren- 

Percentage 
of 

Temperature 
in  Fahren- 

Percentage 
of 

Scale. 

Expansion. 

heit's  Scale. 

Expansion. 

heit's  Scale. 

Expansion. 

31.40 

0 

54.33 

5.5 

74.30 

11.0 

33.54 

0.5 

56.24 

6.0 

75.94 

11.5 

35.70 

1.0 

58.12 

6.5 

77.23 

12.0 

37.84 

1.5 

60.02     . 

7.0 

78.81 

12.5 

39.91 

2.0 

62.00 

7.5 

80.40 

13.0 

42.05 

2.5 

63.77 

8.0 

81.94 

13.5 

44.17 

3.0 

65.63 

8.5 

83.44 

14.0 

46.22 

3.5 

67.43 

9.0 

84.88 

14.5 

48.25 

4.0 

69.18 

9.5 

86.39 

15.0 

50.32 

4.5 

70.90 

10.0 

87.83 

15.5 

52.36 

5.0 

72.60 

10.5 

89.20 

16.0 

Thus  if  the  holder  temperature  is  59°,  that  of  the  meter  61°, 
when  the  meter  registers  5  cu.  ft.,  the  holder  indicates  4.9  cu.  ft. 
Then  4.9X2X0.0025  =  0.025,  which  .must  be  added  to  the  holder 
indication,  making  4.925  cu.  ft.,  which  is  0.075  cu.  ft.  fast,  or -1.42 
per  cent.  If  the  temperature  of  the  meter  is  the  lower,  the  correc- 
tion for  the  volume  must  be  subtracted  instead  of  added  to  get 
the  correct  holder  indication. 


CHAPTER  XVI. 
PRESSURE. 

THE  question  of  pressure  is  one  which  must  be  determined 
solely  from  local  conditions,  the  basis  of  which  must  necessarily  be 
the  extreme  terminus  of  the  distribution  system,  or,  in  other  words, 
the  minimum  pressure  must  be  the  unit  from  which  all  calculations 
are  to  be  made. 

Adequate  Pressure. — Pressure  can  at  all  times  be  reduced 
through  means  of  district  or  house  governors,  but  the  initial  pressure 
is  only  increased  by  an  elevation  in  topography,  which  is  equivalent 
approximately  to  0.1  in.  of  water  for  each  rise  of  15  ft.  above  the 
outlet  of  the  holder.  On  the  other  hand,  the  loss  of  pressure  due 
to  friction  is  enormous,  which  reduction  is  materially  increased  by 
sharp  bends  in  the  pipe-line.  The  initial  pressure,  therefore,  must 
be  governed  by  the  minimum  pressure  allowable  or  the  pressure 
that  is  necessary  to  deliver  in  the  most  remote  sections  of  the  system. 

Loss  of  pressure  through  friction  can,  of  course,  be  largely  ob- 
viated by  increasing  the  diameter  of  the  main,  the  capacity  of  gas- 
pipes  varying  as  the  square  root  of  the  fifth  power  of  the  diameter. 
The  most  convenient  way  for  maintaining  an  equalized  pressure 
throughout  an  entire  system  is  to  establish  a  series  of  testing- 
stations,  or  of  locating  Bristol  recording  gages  in  various  localities 
and  observing  from  these  the  minimum  pressure  prevailing  at 
"peak  of  load"  hours. 

In  using  the  expression  "minimum  pressure"  the  writer  means 
the  peak  of  the  load-line  as  observed  on  a  Bristol  chart  during  the 
heaviest  day's  consumption  during  the  year.  A  record  of  these 
tests  should  be  kept  from  year  to  year,  as  an  increase  of  consump- 
tion in  any  district,  or  other  district  adjacent  or  connected  thereto, 
will  cause  so  material  a  drop  in  pressure  as  to  seriously  affect  the 
service,  and  if  a  comparison  is  kept  up  throughout  the  lighter 
burning  months,  together  with  previous  records,  such  a  drop  may 
be  anticipated  and  larger  mains,  or  other  expedients  such  as  cross 

216 


PRESSURE.  217 

connections,  the  running  of  feed-lines,  or  the  tapping  in  of  a  booster- 
line  or  high-pressure  line,  can  be  arranged. 

To  facilitate  calculations  as  to  the  size  of  pipe  requisite,  a  Cox 
gas-flow  computer  can  be  had  from  any  of  the  gaslight  journals 
which  will  be  found  very  convenient  in  determining  the  size  and 
pressure  drop  in  various  pipes. 

Pressure  is  also  frequently  affected  by  traps  of  tar  or  other  con- 
densation occurring  in  the  pipes,  and  of  a  failure  to  pump  drips  at 
proper  intervals.  A  regular  card  system  should  be  maintained 
containing  a  record  of  the  pumping  of  each  drip,  its  location,  capac- 
ity, etc.,  and  these  drips  should  be  gone  over  periodically. 

The  question  of  house  pressure,  or  burner  pressure,  is  a  vital 
one  and  of  constant  occurrence  in  the  handling  of  complaints.  In 
the  examination  of  poor  lighting  conditions  in  a  house  or  other  in- 
stallation, the  pressure  test  should  be  a  first  consideration.  The 
first  test  should  be  made  on  the  service  side  of  the  meter  and  a 
record  made  thereof.  The  next  test  should  be  made  on  the  house 
side  of  the  meter,  and  a  simple  deduction  of  the  two  readings  will 
indicate  the  loss  of  pressure  due  to  the  meter  normally,  0.2  in., 
sometimes  caused  by  a  stoppage,  condensation,  breaking  of  parts, 
or  a  stiffening  of  the  meter-diaphragm.  It  must  be  remembered 
that  loss  of  pressure  is  invariably  due  to  friction,  and  that  without  a 
flow  of  gas  no  friction  can  exist.  Therefore,  in  order  to  make  any 
pressure- test,  it  is  necessary  to  create  a  gas  flow,  which  is  best  done 
by  lighting  all  the  burners  possible  in  the  installation  and  thereby 
obtaining  the  reduction  of  pressure  at  maximum  demand.  A  com- 
parison can  then  be  made  by  gradually  reducing  the  amount  of  con- 
sumption and  noting  the  ratio  of  reduction  of  friction  and  increase 
of  pressure,  this  being  an  invariable  test  for  piping  which  is  too 
small,  stopped,  etc.,  etc.  The  pressure  reduction  between  full  load 
and  no  load  on  any  system  should  be  less  than  20  per  cent.  A 
finely  calibrated  water-gage,  carefully  read  throughout  the  branches 
of  a  house-system,  will  indicate  at  just  what  point  the  friction  is 
extreme  or  first  evident. 

A  careful  investigation  of  the  distribution  conditions  of  a  num- 
ber of  cities,  and  an  examination  into  the  nature,  construction,  and 
capacity  of  a  number  of  gas  appliances,  pipe  systems,  etc.,  goes  to 
show  the  necessity  of  a  maintenance  at  the  consumer's  meter  of  a 
pressure  not  less  than  2  in.  The  maximum  pressure  is,  of  course,  a 
matter  of  local  conditions  and  necessity,  the  minimum  being  the 
unit  of  consideration  and  calculation.  It  should  on  low-pressure 
systems  be  at  least  less  than  4  in.  and  preferably  under  3  inches  on 
account  of  leakage. 

It  is,  of  course,  understood  in  all  references  to  pressure  that  the 
weight  of  a  column  of  water  27.77  inches  in  height  is  1  Ib.  per  sq. 


218 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


in.,  one  inch,  therefore,  being  1/27  pound.  Correlatively,  1  ounce 
per  sq.  in.  =  1.74  inches  water  pressure.  Generally  0.036  time  the 
height  of  water-column  in  inches  equals  the  pressure  of  water  in  Ibs. 
per  sq.  in. 

It  will  be  found  convenient  when  investigating  poor  pressure 
to  take  the  pressure  of  adjacent  services  before  taking  the  house- 
pipe  pressure  and  by  comparison  locate  stoppages,  should  there  be 
any,  in  the  service  or  the  immediate  district  of  the  main. 

Governors. — The  rattling  or  vibration  of  the  dry-pressure  regu- 
lator or  governor  is  invariably  caused  by  its  being  insufficient  in 
size,  either  to  pass  the  amount  of  gas  demanded  or  to  accommodate 
a  pressure  considerably  in  excess  of  that  for  which  the  governor  was 
designed.  The  matter  may  be  corrected  either  by  putting  in  a 
governor  or  regulator  of  larger  capacity,  or  by  placing  two  or  more 
governors  in  series. 

Two  cuts  of  governors  are  herewith  appended  (Figs.  56,  57), 
namely,  the  Automatic  and  the  Foulis  air  control  governors.  The 


FIG.  56. — Connelly  Automatic 
Station  Governor. 


FIG.  57.— Foulis  Street 
Governor. 


objection  to  the  Automatic  governor  is:  Where  peak  loads  come 
on  suddenly  and  from  widely  outlying  districts,  the  pressure-area 
must  become  low  throughout  the  entire  system  before  the  governor 
responds,  thus  making  the  response  regulation  somewhat  slow.  The 
tendency  with  an  automatic  governor  is  naturally  not  to  give  it  the 
close  attention  which  is  demanded  by  the  hand  control,  and  in  this 
connection  the  action  of  the  Foulis  regulator  is  accurate  and  simple, 


PRESSURE.  219 

permitting  a  wide  range  of  adjustment.  This  governor  is  especially 
favorable  to  situations  on  high-pressure,  or  booster,  lines ;  it  is  ap- 
plicable to  street  manholes,  the  air-line  being  run  to  some  con- 
venient point  within  a  radius  of  1000  yards. 

Excellent  house  or  local  governors  are  made  by  the  Connelly 
Company  and  the  Chaplin  &  Fulton  Company. 

Pressure=gages. — The  differential  piessure-gage  illustrated  by 
Fig.  59,  as  designed  by  the  writer  some  years  ago;  has  been  found 
of  extraordinary  value  in  the  location  of  stoppages,  back  pressure, 
etc.,  throughout  the  apparatus  and  connections  of  gas-works.  It 
consists  of  a  series  of  any  number  of  brass  T's  (A),  connected 
together  by  short  nipples,  and  the  whole  clamped  for  convenience 
against  the  pressure-board.  In  the  center  a  large  U  pressure- 
gage  (B)  is  connected,  having  a  capacity  up  to  several  pounds  and 
graduated  down  to  0.1  in.  water  pressure. 

Cut  into  the  riser  of  the  gage  at  E  is  a  relief-cock,  to  relieve 
compression  between  making  tests  and  to  permit  the  fluid  in  the 
gage  to  return  to  zero. 

A  number  of  pressure-lines,  which  may  be  as  small  as  f-in. 
pipe  (D),  are  run  from  various  portions  of  the  works  from  different 
apparatus  and  sections  of  mains.  These  should  be  properly  labeled 
and  are  connected  into  the  male  outlet  of  the  T's,  brass  cocks  (C) 
being  interposed. 

It  will  now  be  evident  that  by  switching-in  upon  the  gage,  one 
at  a  time,  any  one  of  these  pressure-lines,  and  by  noticing  the  dif- 
ference in  pressure  between  two  or  more,  the  approximate  location 
of  any  stoppage  or  back  pressure  may  be  immediately  located  and 
the  difficulty  eventually  corrected. 

On  mains  where  there  are  no  high-pressure  booster- lines  or 
sub-station  governors  it  is  often  difficult  at  the  works  to  deter- 
mine exactly  the  hours  of  peak  load  and  the  moment  of  maximum 
demand.  To  overcome  this  difficulty,  and  to  indicate  at  the  holder 
any  increase  or  demand,  requiring  additional  pressure  and  supply, 
W.  A.  Baehr,  of  the  Laclede  Gaslight  Co.,  has  designed  the 
following  device.  His  idea  is  that  the  essential  principle  of 
pressure  regulation  is  to  maintain  a  certain  pressure  at  the  con- 
sumers' meters,  within  a  small  percentage  either  way  of  a  fixed 
pressure,  and  as  the  consumption  increases  or  decreases,  the  holder 
pressure  should  be  correspondingly  raised  or  lowered.  This  is 
usually  accomplished  by  placing  recording  pressure-gages  in  the 
various  districts  supplied  by  the  holder,  and  by  raising  or  lowering 
the  holder  pressure  to  supply  the  demand,  as  reflected  from  the 
charts  of  these  gages,  until  the  best  average  for  the  entire  district 
so  supplied  is  reached. 

It  is,  of  course,  obvious  that  the  same  condition  of  consump- 


220 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


tion  never  obtains  on  successive  days  or  months,  and  therefore 
Mr.  Baehr  has  arranged  an  automatic  indicator  in  the  outlet-pipe 
of  his  holder.  This  consists  of  a  Pitot  tube  facing  the  holder. 


The  opening  in  the  tube,  which  faces  the  stream  of  flowing  gas, 
gives  the  pressure  due  to  the  sum  of  the  static  head  plus  the  im- 
pact or  velocity  head;  whereas  the  side  opening  gives  the  pressure 
due  to  the  static  head  only;  therefore  any  variation  in  the  way 


PRESSURE. 


222 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


of  flow  of  gas  is  at  once  reflected  by  the  variation  in  differential 
pressure  between  the  two  openings  of  the  Pitot  tube.     By  using  a 


Center  Llue  of  Vain 


FIG.  61 . — Pitot  Tube  for  Measuring  Velocity-head  of  Gas  Flowing  in  Pipes. 

very  sensitive  differential  pressure-gage  the  variations  of  flow  can 
readily  be  observed.  It  is  of  course  necessary  to  calibrate  these 
gages  for  each  particular  holder,  in  order  to  read  direct  or  to  ascer- 


PRESSURE.  223 

tain  the  variation  in  pressure  of  the  holder  necessary  to  supply 
any  particular  demand.  The  Laclede  Gaslight  Go.  of  St.  Louis, 
Mo.,  use  three  types  of  sensitive  differential  gages,  provided  with 
two  scales,  one  of  which  shows  a  division  in  millimeters  and  the 
other  reading  gives  directly  the  proper  pressure  to  be  carried  on 
the  holder  outlets. 

An  excellent  ink  for  recording-gage  pens  may  be  made  of 
glycerine,  colored  with  a  solution  in  alcohol  of  fuchsine,  cochineal, 
or  any  other  aniline  coloring-matter,  a  sufficient  quantity  being 
added  to  bring  it  to  proper  viscosity. 

It  will  be  kept  in  mind  that  increasing  the  pressure  increases 
the  consumption,  and  that  main  and  pipe  leakage  increase  at  the 
same  time. 

Engine  Pulsations. — It  is  often  the  case,  where  a  gas-engine 
is  connected  to  a  comparatively  small  street  main,  for  its  opera- 
tion (especially  where  this  engine  is  of  multiple-cycle  type)  to 
cause  a  considerable  pressure  fluctuation  in  the  adjacent  gas  sup- 
ply, causing  disturbance  of  the  district  lighting.  To  correct  this 
there  are  various  devices,  some  of  which  are :  Connecting  two  large 
gas-bags  to  the  pipe,  between  the  engine  and  the  gas-meter;  or 
putting  in  two  pipes  of  three  or  four  times  the  diameter  of  the 
engine  supply-pipe  between  the  engine  and  meter,  or  meter  and 
service;  or  cutting  in  a  stop-cock  after  the  meter,  and  turning 
this  down  in  such  a  manner  as  to  supply  the  gas-bag  or  bags  at  a 
practically  uniform  rate,  and  therefore  make  a  practically  con- 
tinuous flow  of  gas.  The  best  method,  especially  in  the  use  of 
multi-cylinder  engines,  is  to  have  a  miniature  holder,  the  seal 
consisting  of  some  non-volatile  liquid.  In  the  interval  of  the 
strokes  of  the  engine  the  supply  of  this  reservoir  is  replenished, 
and  the  pressure  of  the  atmosphere  against  this  seal  and  holder 
crown  tends  to  cushion  any  pulsation  which  may  occur.  This  is 
unquestionably  the  best  form  of  vibration  reducer,  but  somewhat 
expensive.  An  old  meter-prover  may  be  utilized,  however. 

The  ordinary  form  of  draught-gage,  consisting  of  a  U  tube  con- 
taining water,  lacks  sensitiveness  when  used  for  measuring  small 
quantities  of  draught.  The  Barrus  draught-gage  multiplies  the  indi- 
cation of  the  ordinary  U  tube  as  many  times  as  may  be  desired. 
This  instrument  consists  of  a  tube,  usually  made  of  J-in.  glass, 
which  is  surmounted  by  two  glass  chambers  having  a  diameter  of 
about  2^  in.,  being  arranged  in  the  manner  shown  in  Fig.  62. 
It  is  placed  in  a  wooden  case  provided  with  a  cover,  the  outside 
dimensions  being  6^X20  in.;  this  is  screwed  to  the  wall  in  an 
upright  position.  Two  different  liquids,  which  will  not  mix  and 
which  are  of  different  color,  are  used  for  filling  the  instrument, 
one  occupying  the  portion  AB  and  the  other,  which  is  the  heavier 


224 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


of   the  two,    the   portion   BCD.      When   the   right-hand  tube   is 
connected  to  the  flue,  the  suction  produced  by  the  draught  draws 
the  line  of  demarcation  B  downward,  and  the  amount 
of  motion  is  proportional   to   the  difference  in  the 
areas  of  the  two  chambers  and  of  the  U  tube,  modi- 
fied somewhat  by  the  difference  in  the  specific  gravity 
of  the  liquids.      By  referring  to  the   scale   on   the 
side  the  amount  of  motion  is  measured.     This  scale 
is  movable,  and  can  be  adjusted  to  the  zero-point 
by  loosening  the  thumb-screws.     The  liquids  generally 
employed  are  alcohol  colored  red  and  a  certain  grade 
of  petroleum  oil.     A  multiplication  varying  from  8  to 
10   times   is   obtained  in  the  instrument  shown;   in 
I   other  words,  with  J-in.  draught,  the  movement  of  the 
|  line  of  demarcation  is  from  2  in.  to  2J  in.,  the  exact 
~"~  amount    of    multiplication    being     determined   by 
FIG.  62. — Bar-  calibration  referred  to  a  standard  instrument, 
rus  Draught-       High  Pressures. — In  conditions  of  high-pressure 
£a&e-  distribution  where  gas  governors  or  regulators  are  used 

and  the  initial  pressure  exceeds  over,  say,  10  inches  of  water,  the 
pressure  regulator  or  governor  should  be  reinforced  by  a  mercury  seal 
and  escape  pipe  or  vent,  which  acts  as  a  safety-valve  or  relief,  saving 
the  meter  or  house  fixture  from  excessive  strain,  in  case  of  a  failure  on 
the  part  of  such  regulator  to  work,  or  rather  to  reduce  the  pressure. 
It  is  the  writer's  practice,  however,  to  merely  connect-in  the 
governor  or  regulator  directly  to  the  service,  interposing  only  a 
proper  service-cock,  then  between  the  governor  and  the  consumer's 
meter  to  interpose  the  seal-pot  in  such  manner  that  excessive 
pressure  escaping  from  the  outlet  of  the  governor  shall  blow  the 
seal  and  escape  through  the  vent-pipe  into  the  open  air;  it  being 
well  to  place  an  alarm  whistle  on  the  outlet  of  such  pipe  to  give 
warning  of  the  escaping  gas  and  the  general  condition  of  affairs. 

In  calculating  the  discharge  from  pipes  conveying  gas  under 
higher  pressures  than  usual,  the  following  formula  is  used,  a  slide- 
rule  computer  having  also  been  made  from  it: 

COX'S   HIGH-PRESSURE   DISCHARGE   FORMULA. 


-33.3J* 


LW 

where  V  =  discharge  in  cubic  feet  per  hour  at  atmospheric  pressure; 
d  =  diameter  of  pipe  in  inches; 

PI  —  absolute  initial  pressure  in  pounds  per  square  inch; 
P2  =  absolute  terminal  pressure  in  pounds  per  square  inch; 
L  =  length  of  pipe  in  miles; 
W  —  specific  gravity  of  gas  when  air=  1. 


PRESSURE.  225 

Where  it  is  desirable  to  transmit  gas  under  a  higher  pressure 
than  ten  pounds  per  square  inch,  positive  pressure-pumps  of  the 
Westinghouse  air-brake  compressor  type  or  the  Laidlaw-Dunn- 
Gordon  Company's  will  be  found  most  efficient  and  satisfactory. 
For  lesser  pressures  heavy-duty  exhausters  (see  chapter  on  Ex- 
hausters) may  be  used. 

Generally  speaking,  the  exhauster  is  employed  where  volume  is 
the  consideration,  and  the  compressor  for  pressure. 

Cox's  Compressed=air  M.E.P.  Computer. — This  computer  is 
designed  to  give  the  theoretical  mean  effective  pressure  due  to  the 
adiabatic  compression  of  air  from  any  initial  to  any  final  pressure, 
and  for  any  altitudes  up  to  15,000  feet.  It  solves  the  formula 

M.E.P.  =  3.463  Pij^)'25- if, 

where  PI  =  initial  absolute  pressure,  and 

P2  =  final  absolute  pressure. 

It  also  gives  the  M.E.P.  for  2-,  3-,  and  4-stage  compression  re- 
duced to  the  low-pressure  cylinder,  assuming  that  the  number  of 
compressions  in  each  cylinder  is  the  same  (this  combination  being 
the  most  economical).  It  is  also  assumed  that  the  intercooling 
reduces  the  temperature  of  the  air  in  each  cylinder  to  that  at  which 
compression  in  the  first  cylinder  began. 

It  further  gives  the  horse-power  developed  in  compressing  100 
cubic  feet  of  free  air  to  the  given  final  gage  pressure. 

DIRECTIONS   FOR    1-STAGE    COMPRESSION. 

1.  Set  the  initial  gage  pressure  on  the  bottom  scale  of  the  disk 
to  the  ratio  of  the  absolute  pressures,  that  is  P2  divided  by  Px. 
This  ratio  may  be  calculated  or  taken  at  once  from  column  2  of  the 
table  accompanying  the  indicator. 

2.  Opposite  the  arrow  on  the  disk  marked  I-STAGE  find  on  the 
top  scale  the  theoretical  mean  effective  pressure  in  pounds  per  sq. 
in.  for  the  whole  stroke. 

FOR   2-,    3-,    OR   4-STAGE    COMPRESSION. 

1.  Set  the   initial  gage  pressure   of   the  first  or  low-pressure 
cylinder  on  the  bottom  scale  of  the  disk  to  the  ratio  of  the  absolute 
pressure  in  each  cylinder,  taken  from  columns  3,  4,  or  5  of  the 
table,  according  to  whether  the  compression  is  to  be  by  2,  3,  or  4 
stages. 

2.  Opposite  the  arrow  on  the  disk  marked  2-,  3-,  or  4-STAGE 
(according  to  the  number  of  compressions  decided  upon)  find  on 


226 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


the  top  scale  the  theoretical  mean  effective  pressure  for  the  whole 
compression,  reduced  to  the  low-pressure  cylinder. 

Note. — When  compressing  from  atmospheric  or  normal  pressure, 
the  initial  gage  pressure  to  be  used  as  above  is  zero  GAGE,  except 
when  seeking  the  M.E.P.  for  a  given  altitude,  in  which  case  the 
given  altitude  must  be  set  opposite  the  pressure  ratio,  instead  of 
zero  initial  gage  pressure. 

To  find  the  horse-power  developed  in  compressing  100  cubic  feet 
of  free  air  to  the  given  final  gage  pressure,  set  the  edge  marked 
M.E.P.  of  the  small  sector  to  the  ascertained  M.E.P.;  then  opposite 
the  arrow  find  the  D.H.P. 

The  following  data,  from  a  paper  read  by  W.  A.  Learned  before 
the  New  England  Association  of  Gas-engineers,  give  some  idea  of 
the  influence  of  compression  upon  city  gas : 

CONDENSATION  DUE  TO  COMPRESSION   OF  GAS. 


39,000 
39,800 
38,200 


li 

111 


5 
10 
20 


1 


150 
179 

280 


41.5 
11.2 
19.9 


0.894 
0.886 
0.889 


Fractional  Distillation  of  Hydrocarbons  which  were 
Condensed,  Degrees  Fahr.  and  Per  Cent. 


6.5 
12 


7.5 
16.3 

18 


19.25 

17.4 

20.9 


15.60 
.9 
10 


016 


00  CO 
CO 


14.13 

13.9 

11.8 


19.15 

20.8 

13.2 


14.37 
8.2 
8.1 


EFFECT  OF  COMPRESSION  ON  CANDLE  POWER  OF  GAS. 


Gas  in  Holder. 

Gas  Pressure  in  Pounds  per 
Square  Inch. 

Kind  of  Gas. 

5. 

10. 

20. 

30. 

14.8    candle  power.  .  . 
16.14       "         "     ... 
1759       "         "     ... 

c.  p. 

c.  p. 
13.2 
15.73 
18.09 

c.p. 

c.p. 

Coal-gas. 

tt 

23  per  cent  water-gas. 
22  "     " 
29  "     "              " 

ieios 

15.48 

1856       "         "     ... 

15.02 

17.10       "         "     ... 

17.30 

16.15 

The  increased  candle  power  and  brilliancy  at  5  Ibs.  compres- 
sion can  be  accounted  for  by  the  decrease  of  the  moisture  in  the 
gas.  Many  attempts  have  been  made  to  dry  the  gas,  with  the 
result  that  when  it  was  deprived  of  its  moisture  the  illuminating 
power  was  increased  to  a  considerable  extent.  ... .r  r. 

The  following  analyses  were  secured  through  the  courtesy  of 
W.  R.  Addicks  and  were  made  by  J.  F.  Wing,  chemist. 


PRESSURE. 


227 


CHEMICAL  ANALYSES  OF  COMPRESSED  GAS. 


Gas  from 
Holder. 

Gas  Compressed, 
Pounds  per  Square 
Inch. 

Gas  from 
Holder. 

Gas  Compressed, 
Pounds  per  Square 
Inch. 

10. 

20. 

20. 

30. 

CO2  

Per  Cent. 
2.5 
6.0 
0.2 
12.3 
50.6 
26.4 
2.1 

Per  Cent. 
2.3 

6.0 
0.0 
12.3 
50.2 
26.7 
2.0 

Per  Cent. 
2.4 

7.0 
0.0 
12.2 
47.3 
25.0 
5.7 

Per  Cent. 
2.0 
6.7 
0.0 

12.6 
49.2 
28.0 
1.5 

Per  Cent. 
2.0 
6.5 
0.0 
13.3 
49.1 
27.1 
2.5 

Per  Cent. 
2.1 
6.7 
0.0 

12.4 
46.6 
27.6 

4.7 

Illuminants  
O2             

CO        

H?  

CH...            

N2..  

Total             

100.1 

99.5 

99.6 

100.0 

100.5 

100.1 

Candle  power.  .  .  . 

17.6 

18.1 

16.06 

18.59 

15.48 

15.02 

VALUES  OF  A  GIVEN  QUANTITY  OF  GAS  AT  DIFFERENT  PRESSURES. 


Capacity  of  a 
Vessel   in 
Cubic  Feet. 

Containing  Gas 
under  a  Pressure 
of 

Will  Contain  the 
Following  Cubic 
Feet  of  Gas. 

100 

4      OZ. 

100. 

100 

8      " 

104. 

100 

16      " 

106. 

100 

1.5  Ibs. 

109.1 

100 

2      " 

111.8 

100 

5      " 

125. 

100 

10      " 

140. 

100 

15      " 

200. 

REGISTRATION  OF  GAS  BY  METER  UNDER  DIFFERENT  PRESSURES. 


Pressure  in 
Ounces  per 

Relative 

Cubic  Fe< 

it  of  Gas. 

Square  Inch. 

Density. 

Passed. 

Registered. 

1 

0.987 

0.500 

0.507 

1.5 

0.989 

0.612 

0.621 

2 

0.991 

0.707 

0.713 

3 

0.996 

0.866 

0.869 

4 

1.000 

.000 

1.000 

5 

1.004 

.118 

1.113 

6 

1.009 

.225 

1.214 

7 

1.013 

.323 

.306 

8 

1.017 

.414 

.390 

9 

1.022 

.500 

.468 

10 

1.026 

1.581 

.541 

11 

1.030 

1.658 

.610 

12 

1.034 

1.732 

1.675 

228 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


THE  EQUIVALENT  OF  OUNCES  PER  SQUARE  INCH  PRESSURE  IN  INCHES  Or 
WATER  AND  OF  MERCURY. 


Ounces. 

Inches  of 
Water. 

Inches  of 
Mercury. 

Ounces. 

Inches  of 
Water. 

Inches  of 
Mercury. 

1 

1.7 

0.125 

9 

15.5 

1.125 

2 

3.4 

0.250 

10 

17.2 

1.250 

3 

5.2 

0.375 

11 

19.0 

1.375 

4 

6.9 

0.500 

12 

20.8 

.500 

5 

8.6 

0.625 

13 

22.5 

1.625 

6 

10.3 

0.750 

14 

24.2 

1.750 

7 

12.0 

0.875 

15 

26.0 

1.875 

8 

13.8 

1.000 

16 

27.7 

2.000 

These  conversion  tables  are  often  useful  in  natural-gas  distri- 
bution : 

HEIGHT   OF   WATER  COLUMN    IN   INCHES   CORRESPONDING   TO  VARIOUS 
PRESSURES  IN  OUNCES  PER  SQUARE  INCH. 


Decimal  Parts  of  an  Ounce. 

Pressure  in 

Ounces  per 
Square  Inch. 

0.0 

O.l 

0.2 

0.3 

0.4 

0 



0.17 

0.35 

0.52 

0.69 

1 

1.73 

1.90 

2.08 

2.25 

2.42 

2 

3.46 

3.63 

3.81 

3.98 

4.15 

3 

5.19 

5.36 

5.54 

5.71; 

5.88 

4 

6.92 

7.09 

7.27 

7.44 

7.61 

5 

8.65 

8.82 

9.00 

9.17 

9.34 

6 

10.38 

10.55 

10.73 

10.90 

11.07 

7 

12.11 

12.28 

12.46 

12.63 

12.80 

8 

13.84 

14.01 

14.19 

14.36 

14.53 

9 

15.57 

15.74 

15.92 

16.09 

16.26 

Pressure  in 

Decimal  Parts  of  an  Ounce. 

Ounces  per 

Square  Inch. 

0.5 

0.6 

0.7 

0.8 

0.9 

0 

0.87 

1.04 

1.21 

1.38 

1.56 

1 

2.60 

2.77 

2.94 

3.11 

3.29 

2 

4.33 

4.50 

4.67 

4.84 

5.01 

3 

6.06 

6.23 

6.40 

6.57 

6.75 

4 

7.79 

7.96 

8.13 

8.30 

8.48 

5 

9.52 

9.69 

9.86 

10.03 

10.21 

6 

11.26 

11.43 

11.60 

11.77 

11.95 

7 

12.97 

13.15 

13.32 

13.49 

13.67 

8 

14.71 

14.88 

15.05 

15.22 

15.40 

9 

16.45 

16.62 

16.79 

16.96 

17.14 

PRESSURE. 


229 


PRESSURES  IN  OUNCES  PER  SQUARE  INCH  CORRESPONDING  TO  VARIOUS 
HEADS  OF  WATER  IN  INCHES. 


Head  in  Inches. 

Decimal  Parts  of  an  Inch. 

0.0 

0.1 

0.2 

0.3 

0.4 

0 

1 

2 

0.58 
1.16 

0.06 
0.63 
1.21 

0.12 
0.69 
1.27 

0.17 
0.75 
1.33 

0.23 
0.81 
1.39 

3 
4 
5 

1.73 
2.31 
2.89 

1.79 
2.37 
2.94 

1.85 
2.42 
3.00 

1.91 

2.48 
3.06 

1.96 
2.54 
3.12 

6 

7 
8 
9 

3.47 
4.04 
4.62 
5.20 

3.52 
4.10 

4.67 
5.26 

3.58 
4.16 
4.73 
5.31 

3.64 
4.22 
4.79 
5.37 

3.70 

4.28 
4.85 
5.42 

Head  in  Inches. 

Decimal  Parts  of  an  Inch. 

0.5 

0.6 

0.7 

0.8] 

0.9 

0 

1 

2 

0.29 
0.87 
1.44 

0.35 
0.93 
1.50 

0.40 
0.98 
1.56 

0.46 
1.04 
1.62 

0.52 
1.09 
1.67 

3 

4 
5 

2.02 
2.60 
3.18 

2.08 
2.66 
3.24 

2.14 
2.72 
3.29 

2.19 
2.77 
3.35 

2.25 
2.83 
3.41 

6 

7 
8 
9 

3.75 
4.33 
4.91 

5.48 

3.81 
4.39 
4.97 
5.54 

3.87 
4.45 
5.03 
5.60 

3.92 
4.50 
5.08 
5.66 

3.98 
4.56 
5.14 
5.72 

Storage=plants. — These  plants  consist  of  a  battery  of  tarks, 
set  firmly  upon  foundations  to  prevent  the  breaking  of  pipe 
connections  under  pulsation,  in  which  gas  is  stored  under  high 
pressure. 

These  batteries  are  connected  through  a  system  of  regulators 
with  the  distributing  mains,  it  being  good  practice,  however,  where 
the  gas  is  stored  under  very  high  pressure  to  "step  down'7  from 
the  high-pressure  battery  to  a  lower-pressure  battery  or  even  a 
single  tank,  through  the  intermediation  of  a  regulator,  and  from 
the  lower-pressure  battery  through  another  regulating  system  to 
the  mains. 


230 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


SPECIFICATIONS   FOR   RECEIVING-TANKS. 
FOR  110  POUNDS  WORKING  PRESSURE. 


i 

OD 

1 

if 

1 

j 

Q 

| 

i 

«  1 

Compressor  Capacity 

•M 

)-4 

1 

"rt  a} 

Q 

Q 

2 

Q 

^ 

*^  ^  of 

Receiver  is  best 

0 

_• 

£ 

Opti 

83       . 

| 

o3   /' 

i 

u-22  c1 

Adapted  for,  in  Cubic 

u 

3 

rH* 

w  O 

«  8 

I 

£ 

-»-  2 

-2 

f 

5Q'fl 

Feet  Free   '  ;r 

1 

1 

f 

|| 

|l 

•SJ 

|l 

II 

III 

per  Minutt. 

1 

s 

3 

| 

H 

H 

s 

5 

0 

18 

6 

10 

if 

H 

350 

i 

2i 

90 

00 

24 

6 

18 

575 

H 

2i 

120 

1 

30 

6 

29 

i 

950 

If 

3 

150 

2 

36 

6 

42 

-  . 

i 

1000 

if 

31 

150  to    200 

3 

36 

8 

56 

-  . 

i 

1350 

M 

4 

200  to    300 

4 

42 

8 

77 

•  . 

•i 

1750 

2 

4 

300  to    500 

5 

42 

10 

96 

j, 

2000 

2 

5 

500  to    700 

6 

48 

12 

150 

~5? 

1 

j 

T 

3000 

2} 

6 

700  to  1200 

7 

54 

12 

190 

A 

V 

3300 

2i 

7 

1200  to  2000 

71 

60 

14 

275 

5500 

2: 

8 

2000  to  3000 

8 

66 

18 

437 

A 

t 

7500 

2^ 

8 

3000  and  over 

1       These  are  only 

9 
10 

24 
36 

6 
6 

18 
42 

i 

I 

625 
1100 

-n--< 
rH  rH 

4 
6 

I  furnished      hori- 
\  zontal  style  and 
1  are  used  as  water- 

J  traps  in  air  lines. 

Number  of  Size. 

11 

12 

13 

14 

15 

16 

17 

18 

Diameter      

30  in. 

36 

in. 

36  in. 

42  in. 

42  in 

48  in. 

54  in. 

66  in. 

Length    .               

6ft. 

6ft. 

8ft. 

8ft. 

10ft 

12ft. 

12ft. 

18ft. 

Thickness  of  shell,  inches. 

\ 

A 

Thickness  of  heads,     " 

1 

I 

f 

f 

I 

A 

JL 

i 

Diameter  of  inlet  and  out- 

let flanges,  inches  

3 

3 

3* 

4 

5 

6 

7 

8 

Diam.  of  safety-valve,  in,,. 
Compressor  capacity  re-  f 
ceiver  is  best  adapt-  -j 

150 
and 

11 

150 
to 

200 
to 

2 
300 
to 

2 
500 
to 

700 
to 

21 

1200 
to 

3 

3000 
and 

ed  for,  pounds             [ 

less 

200 

300 

500 

700 

1200 

3000 

above 

Weight,  about,  pounds  .  .  . 

800 

1150 

1400 

1900 

2100 

3200 

3600 

6000 

FOR  150  POUNDS  WORKING  PRESSURE.     TESTED  TO  225  POUNDS  WATER 

PRESSURE. 


11 

18 

6 

10 

^ 

, 

400 

1 

21 

135 

12 

24 

6 

18 

& 

j 

725 

ll 

21 

180 

13 

30 

6 

29 

A 

1 

975 

1} 

3 

225 

14 

36 

6 

42 

g 

i 

1300 

u 

31 

225  to  300 

15 

36 

8 

56 

i 

1600 

1* 

4 

300  to  450 

16 

42 

8 

77 

» 

A 

2075 

2 

4 

450  to  750 

17 

42 

10 

96 

* 

A 

2550 

2 

5 

750  to  1050 

18 

48 

12 

150 

A 

1 

4000 

2| 

6 

1050  to  1800 

19 

54 

12 

190 

JL 

\ 

4650 

2} 

7 

1800  to  3000 

20 

60 

14 

275 

i 

A 

7350 

2| 

8 

3000  to  4500 

PRESSURE. 


231 


The  connections  of  the  battery  and  the  entire  system  should 
be  as  "  flexible "  as  possible,  permitting  the  use  of  any  unit  at 
any  time  and  the  addition  of  other  units  to  extend  the  capacity 
of  the  plant.  There  is  of  course  an  economical  ratio  existing 
between  the  cost  of  additional  storage  capacity  and  the  cost  of 
compression;  this  must  in.  all  instances  be  determined. 

A  standard  size  of  tank  heretofore  adopted  by  some  of  the 
Western  companies  is  a  tank  6  feet  in  diameter  by  30  feet  long, 
with  reinforced  manhole  fitted  with  cover  and  yoke,  reinforced 
2-inch  outlet  and  inlet,  and  reinforced  1-inch  drip  outlet.  The 
tanks  must  be  placed  upon  their  foundations  so  as  to  avoid  any 
possibility  of  an  unequal  strain  throughout  its  length,  as  a  leak 
once  started  in  high-pressure  tanks  is  most  difficult  of  repair.  The 
tanks  of  the  dished-head  type  are  most  satisfactory.  In  the  in- 
stallation the  tanks  should  receive  the  greatest  care. 

On  the  opposite  page  are  given  the  specifications  for  a  few  of 
the  receiving-tanks  made  by  the  Bury  Compressor  Company. 

These  receivers  are  provided  with  manholes  and  can  be  furnished 
to  rest  vertically  or  horizontally,  the  price  for  either  being  equal 
for  equal  sizes.  Companion  flanges  are  regularly  supplied. 

Made  of  60,000  pounds  t.  s.  steel.  All  longitudinal  seams 
double-riveted.  Girth  seams  single-riveted.  Heads  dished,  both 
convex.  Tested  and  made  tight  under  165  pounds  water  pressure. 
Warranted  safe  and  tight  under  110  pounds  working  pressure. 

The  Bury  Company  recommend  the  placing  of  the  compressor 
at  a  distance  not  less  than  50  feet  from  the  storage-plant. 

Absolute  Pressure. — To  find  real  or  absolute  pressure,  which  is 
necessary  in  all  formulas  concerning  gas,  steam,  or  air,  unless 
gage  pressure  is  distinctly  specified,  atmospheric  pressure  must 
be  added  to  gage  pressure  (usually  14.7  Ibs.  at  sea-level). 

RELATIVE  CARRYING  CAPACITY  OF  GAS-PIPES. 
(  NOR  WALK  IRON  Co.) 


Comparative  Capacity. 

Comparative  Capacity. 

Diameter, 

Diameter, 

Inches. 

Delivery  of 

Area  of 

Inches. 

Delivery  of 

Area  of 

Gas. 

Section. 

Gas. 

Section. 

24 

1.0 

1.00 

4 

0.0102 

0.0278 

12 

0.17 

0.25 

3* 

0.0069 

0.0212 

10 

0.10 

0.175 

3 

0.0045 

0.0156 

8 

0.06 

0.111 

2* 

0.002835 

0.0108 

7 

0.04 

0.085 

2 

0.001485 

0.0069 

6 

0.03 

0.0625 

1J 

0.000810 

0.0039 

5 

0.0189 

0.0434 

ll 

0.000450 

0.00272 

4* 

0.0141 

0.0351 

0.000225 

0.00173 

232 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TRANSMISSION  OF  GAS  OF  0.55  SPECIFIC  GRAVITY  THROUGH  A  PtPE  WITH 

90°  BENDS. 

(NELSON  W.  PERRY.) 


Inches 
Pressure. 

Cubic  Feet 
Delivered. 

Velocity  of 
Flow  in  Cubic 
Feet  per 
Second. 

Increase  of 
Pressure 
per  Bend, 
Inches. 

Total 
Increased 
Pressure  for 
25  Bends, 
Inches. 

Total  Initial 
Pressure, 
Inches. 

1 

12,500 

4.0 

0.0016 

0.04 

1.04 

2 

18,000 

6.0 

0.0034 

0.085 

2.085 

3 

23,000 

8.0 

0.006 

0.1495 

3.15 

4 

25,500 

8.8 

0.0076 

0.189 

4.189 

5 

28,000 

9,6 

0.0086 

0.215 

5.215 

6 

32,000 

11.0 

0.0113 

0.28 

6.28 

7 

34,000 

12.0 

0.0135 

0.34 

7.34 

8 

36,000 

12.5 

0.0147 

0.39 

8.39 

9 

38,500 

13.0 

0.0158 

0.4 

9.4 

10 

40,000 

14.0 

0.0183 

0.46 

10.46 

HIGH-PRESSURE  GAS  DELIVERY. 
(F.  H.  OLIPHANT.) 

Cubic  feet  per  hour  =  42a i/  — -JP. 

P  and  p  are  gage  pressures  at  intake  and  discharge  ends  of  pipe  plus  15 
Ibs.;  I  is  length  in  yards;  a  for  different  sizes  of  pipe  is: 


Diameter 
Inside. 

a 

Diameter 
Inside. 

a 

Diameter 
Inside. 

Diameter 
Outside. 

a 

0.25 
0.50 
0.75 
1.0 

1.5 
2.0 
2.5 
3.0 

0.0317 
0.1810 
0.5012 
1.0000 

2.9300 
5.9200 
10.3700 
16.5 

4 

5 
6 

8 

10 
12 
16 
18 

34.1 
60 
96 
198 

350 
556 
1160 
1570 

14.25 
15.25 
17.25 
19.25 
Riveted 
20 
24 
30 
36 

15 
16 
18 
20 
or  cast-iro 

863 
1025 
1410 
1860 
n  pipes 
2055 
3285 
5830 
9330 



Flow  of  Gases  in  Pipes. — The  following  notes  upon  Dr.  Pole's 
formula  for  the  flow  of  gases  in  pipes  have  been  made  by  F.  S. 
Cripps  and  published  in  the  Journal  of  Gas  Lighting.  Let 

Q= discharge  of  gas  in  cubic  feet  per  hour; 
d= diameter  of  pipe  in  inches; 
p= pressure  of  gas  in  inches  of  water; 
s= specific  gravity  of  gas,  air  equalling  1; 
1=  length  of  pipe  in  yards. 


PRESSURE. 


233 


From  the  above  it  is  apparent  that,  other  things  being  equal — 


Q  varies  directly  as    V  p 

' '        inversely  as  v7/ 

tt  «         «  \/g 

d  varies  directly  as    \/Q2 


p  varies  directly  as 


inversely  as  d5 
I  varies  directly  as    p 
"  "        "     d5 

11        inversely  as  Q2 


'  '       inversely  as  v  p 

s  varies  directly  as    p 

a  «          (  (       x^5 

'  '       inversely  as  Q2 


A  consideration   of  the  foregoing  gives  rise  to  the  following 
axioms  or  rules: 

QUANTITY—  PRESSURE. 

Double  the  quantity  requires  four  times  the  pressure. 
Or,  four  times  the  pressure  will  pass  double  the  quantity. 
Half  the  quantity  requires  one  fourth  the  pressure. 
Or,  one  fourth  the  pressure  is  sufficient  for  half  the  quantity, 


234  AMERICAN  GAS-ENGINEERING  PRACTICE. 

QUANTITY — LENGTH. 

Double  the  quantity  can  be  discharged  through  one  fourth  the 
length. 

Or,  one  fourth  the  length  will  allow  of  double  the  discharge. 
Half  the  quantity  can  be  discharged  through  four  times  the  length. 
Or,  four  times  the  length  reduces  the  discharge  one  half. 

QUANTITY — DIAMETER. 

Thirty-two  times  the  quantity  requires  a  pipe  four  times  the 
diameter. 

Or,  a  pipe  four  times  the  diameter  will  pass  thirty-two  times  as 
much  gas. 

A  pipe  one  fourth  the  diameter  will  pass  one  thirty-second  of 
the  quantity. 

Or,  one  thirty-second  of  the  quantity  can  be  passed  by  a  pipe 
one  fourth  the  diameter. 

QUANTITY — SPECIFIC    GRAVITY. 

The  specific  gravity  stands  in  just  the  same  relation  to  the 
volume  as  the  length  does  (see  Axioms  3  and  4). 

PRESSURE — LENGTH. 

If  the  pressure  is  doubled  the  length  may  be  doubled. 

Ard,  conversely,  if  the  length  be  doubled  the  pressure  must  be 
doubled. 

If  the  pressure  be  halved  the  length  may  be  halved. 

And,  conversely,  if  the  length  be  halved  the  pressure  must  be 
halved. 

From  Axioms  8  and  9  it  is  evident  that — 

The  pressure  required  to  pass  a  given  quantity  of  gas  varies 
exactly  as  the  length  of  the  pipe. 

PRESSURE — SPECIFIC   GRAVITY. 

The  pressure  required  to  pass  a  given  quantity  of  gas  also 
varies  exactly  as  the  specific  gravity  of  the  gas.  Hence  if  the 
specific  gravity  of  the  gas  were  doubled,  double  the  pressure  would 
be  required. 

PRESSURE — DIAMETER. 

One  thirty-second  part  of  the  pressure  is  sufficient  if  the  diam- 
eter be  doubled ;  or,  in  other  words,  if  you  double  the  diameter  you 
require  only  one  thirty-second  of  the  pressure  to  pass  the  same 
quantity  of  gas. 


OF    1 

UNIVERSITY 

Of 


PRESSURE.  235 


If  you  halve  the  diameter,  thirty-two  times  the  pressure  is  re- 
quired. 

And,  conversely,  if  you  increase  the  pressure  thirty-two  times, 
the  diameter  can  be  halved. 

LENGTH — DIAMETER. 

The  length  can  be  increased  thirty-two  times  if  the  diameter  be 
doubled. 

And,  conversely,  if  the  diameter  be  doubled,  the  length  can 
be  increased  thirty- two  times  and  pass  the  same  quantity  of  gas. 

If  the  diameter  be  halved,  the  length  must  be  reduced  to  one 
thirty-second  to  pass  the  same  quantity  of  gas. 

And,  conversely,  if  the  length  be  made  one  thirty-second  of  the 
distance,  the  diameter  may  be  halved. 

SPECIFIC    GRAVITY — LENGTH. 

If  the  specific  gravity  be  doubled,  the  length  must  be  halved, 
and  vice  versa,  to  satisfy  the  equation. 

SPECIFIC    GRAVITY — DIAMETER. 

The  specific  gravity  follows  the  same  laws  as  the  length  docs 
in  relation  to  the  diameter. 

It  must  be  borne  in  mind,  when  using  the  above  rules,  that  all 
other  conditions  remain  the  same  when  considering  the  effect  of 
one  factor  on  another  in  the  different  pairs. 

The  above  may  be  found  convenient  for  rule-of-thumb  calcu- 
lations. 

COMPARISON   OF   FORMULAE. 

Mr.  Oliphant  has  checked  certain  formulae  on  delivering  natural 
gas  100  miles  into  a  gas-holder  through  8-inch  pipe. 

Taking  the  Newton  conditions  and  using  the  several  formulae 
we  obtain  the  following  results: 

Formula.  Calculated  Cu.  Ft.  per  Hour. 

(Actual  volume  delivered) (18,200) 

Pittsburg 18,380 

Cox's 16,000 

Oliphant's 16,260 

corrected 17,510 

Robinson's 18,730 

Unwin's 31.870 

Velde's 22  060 

Richards'  (corrected  for  0.6— g  gas) 18,708 

Hiscox's  (corrected  for  0.6 — g  gas) 16,250 

Lowe's. .  26,910 


CHAPTER  XVII. 
HOUSE    PIPING. 

SPECIFICATIONS   FOR  HOUSE  PIPING. 

FIRST.  The  piping  must  stand  a  pressure  of  3  Ibs.  per  square 
inch,  or  6  in.  of  mercury  column,  without  showing  any  drop  in  the 
mercury  column  of  the  gage  for  a  period  of  ten  minutes.  After 
the  fixtures  are  in  place,  the  piping  and  fixtures  must  stand  the 
same  test.  However,  when  on  third  inspection  there  are  any  old 
fixtures  under  test,  the  pressure  required  will  be  only  8  in.  of 
water  column.  Leaky  fittings  or  pipe  must  be  removed;  cement- 
patched  material  will  be  rejected. 

Second.  The  sizes  of  pipe  shall  not  be  less  than  are  called  for 
in  the  table  shown  on  page  240.  This  table  shows  for  any  given 
number  of  outlets  the  greatest  length  allowed  for  each  size  of  pipe. 

Third.  The  piping  must  be  free  from  obstructions.  Every 
piece  of  pipe  should  be  stood  on  end  and  thoroughly  hammered  and 
blown  through  before  being  connected.  Use  white  lead  or  other 
jointing  material  sparingly,  to  avoid  clogging  the  pipe.  Always 
put  jointing  material  on  the  male  thread  on  end  of  pipe,  and  not 
in  the  fitting.  The  use  of  gas-fitters'  cement  is  prohibited.  All 
piping  should  be  blown  through  after  beirg  connected,  to  make 
sure  it  is  clear. 

Fourth.  All  piping  must  be  free  from  traps.  All  pipes  shall 
grade  back  toward  the  riser,  and  thence  to  the  meter;  use  a  spirit- 
level  in  grading.  Any  pipe  laid  in  a  cold  or  damp  place  should  be 
properly  dripped  and  protected. 

Fifth.  The  piping  must  be  rigidly  supported  by  hooks  and 
straps.  Outlets  for  brackets  or  drops  must  be  secured  by  straps 
or  flanges,  which  are  nailed  or  screwed  to  the  woodwork.  Where 
the  walls  are  not  masonry,  they  should  be  plugged  and  the  straps 
fastened  to  the  plugs. 

Sixth.  The  riser  must  extend  to  a  poirt  within  24  in.  of  the 
proposed  location  of  the  meter,  and,  if  a  horizontal  line  is  needed, 

236 


HOUSE  PIPING.  237 

a  tee,  with  plug  looking  down,  must  be  put  on  the  bottom  of  the 
vertical  pipe.  In  piping  new  houses  the  gas-fitter  should  decide 
where  the  gas-meter  ought  to  be  located,  and  extend  the  riser  to 
terminate  within  24  in.  of  this  point.  In  determining  the  proper 
location  of  the  meter,  he  should  be  guided  by  the  following : 

Meters. — Meters  must  not  be  located  under  stoops,  sidewalks, 
or  show-windows,  near  furnaces  or  ovens,  locked  in  compart- 
ments, nor  placed  in  any  other  situation  where  they  will  be  inac- 
cessible or  liable  to  injury. 

If  the  building  is  on  a  street  corner,  the  company  should  be 
asked  from  which  street  the  service  will  be  run,  and  where  the 
meter  should  be  located.  If  at  any  time  the  fitter  is  in  doubt  as 
to  the  future  location  of  a  meter,  on  application  to  the  proper 
office,  some  one  will  be  sent  to  instruct  him. 

Where  more  than  one  meter  is  desired  in  a  given  building,  to 
accommodate  different  tenants,  the  company  will  set  as  many 
meters  as  there  are  separate  consumers,  connecting  them  to  one 
service-pipe,  provided  that  the  risers  or  pipes  leading  to  the  dif- 
ferent tenants  are  extended  to  within  a  reasonable  distance  (say 
6  ft.)  of  the  actual  or  proposed  location  of  service.  All  the  meters 
must  stand  side  by  side  in  the  cellar  or  basement,  within  view  of 
the  end  of  the  service.  The  company  will  not  set  meters  on  the 
different  floors  of  a  building.  Risers  must  not  be  scattered,  but 
must  drop  together  to  the  cellar  or  basement,  preferably  in  front 
part  of  building.  They  should  not  extend  more  than  3  in.  below 
bottom  of  joists,  and  should  be  kept  at  least  3  in.  apart.  They 
must  never  end  in  such  a  place  that  beams,  girders,  heater-pipes, 
etc.,  to  be  put  up  subsequently,  would  prevent  making  connections 
to  the  meter. 

Always  use  fittings  in  making  turns;  do  not  bend  pipe.  Do 
not  use  unions  in  concealed  work;  use  long  screws  or  right  and 
left  couplings.  Long  runs  of  approximately  horizontal  pipe  must 
be  firmly  supported  at  short  intervals  to  prevent  sagging.  All 
horizontal  outlet-pipes  must  be  taken  from  the  sides  or  tops  of 
running  lines,  never  from  below. 

All  ceiling  outlets  must  project  not  more  than  2  in.  nor  less 
than  f  in.,  and  must  be  firmly  secured  and  perfectly  plumb.  Side- 
wall  outlets  must  project  not  more  than  f  in.,  and  must  be  at  right 
angles  to  the  wall  and  be  firmly  secured. 

Where  pipes  pass  through  masonry  walls  they  must  be  en- 
cased, the  gas-pipe  resting  on  the  bottom  of  the  casing-pipe  with 
a  clearance  of  half  an  inch  on  top. 

Pipes  must  be  so  run  and  covered  as  to  be  readily  accessible. 
Do  not  run  them  at  the  bottom  of  floor-beams  which  are  to  be 
lathed  and  plastered.  They  must  be  securely  attached  to  the  top 


238 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


of  the  beams,  which  should  be  cut  out  as  little  as  possible.  Where 
pipes  are  paralleled  to  beams,  they  must  be  supported  by  strips 
nailed  between  two  beams.  These  strips  must  be  not  over  4  ft. 
apart.  All  cutting  of  beams  should  be  done  as  near  as  possible  to 
the  ends  or  supports  of  the  beams.  Pipes  must  not  be  laid 
beneath  tiled  or  parquet  floors,  under  marble  platforms,  or  under 
hearthstones,  where  it  can  be  avoided.  Floor-boards  over  pipes 
should  be  fastened  down  by  screws,  so  that  they  can  readily  be 
removed. 

No  stove  line  must  be  used  for  lighting  purposes  without  first 
obtaining  permission  from  the  company. 

Requirements  for  Gas-fixtures. — 1.  All  fixtures  for  outside 
lighting  must  be  made  so  that  at  all  traps  there  is  provision  for 
letting  out  condensation. 

2.  Pendants  must  be  made  as  follows : 


When  » 

lade  of 

Length  of  Pendant  Over  All. 

Iron  Pipe, 
in.  diam. 

Brass  Pipe, 
in.  diam. 

f 

2  ft  9  in  and  under 

i 

3 

One-piece  pendants.  .  .  < 

Over  2  ft  9  in                 ... 

! 

f 

Harp  or  "C  "  pendants 

Any  length            

1 

» 

Length  of  pendant  over  all  is  understood  to  be  the  distance  in 
a  straight  line  from  the  stiff  joint  to  the  lowest  part  of  the  pendant. 

3.  Arms  of  gas-fixtures,  or  those  parts  which  carry*  the  gas 
from  only  one  burner-nozzle,  must  be  of  the  following  sizes: 


Length  of  Arms. 

Iron  Pipe. 

Brass  Pipe, 
in.  diam. 

Cased, 
in.  diam. 

Uncased, 
in.  diam. 

12  in.  or 
From  12 
Over  18 

shorter  .  .                    

! 

I 

! 

in.  to  18  in.  inclusive  

in  

When  Made  of 


Length  of  arm  is  understood  to  be  the  distance  in  a  straight 
line  from  the  center  of  the  stem  to  the  center  of  the  burner. 

4.  Stems  of  2-light  straight  or  toilet  pendants  must  be  made 
as  follows  *. 


HOUSE   PIPING. 


239 


Length  of  Pendant  Over  All. 

When  Made  of  Iron  Pipe. 

Cased, 
in.  diam. 

Uncased, 
in.  diam. 

2  ft.  6  in. 
Over  2  ft. 
3  ft.  6  in. 

and  under 

i 

1 

6  in  and  under  3  ft   6  in 

and  over 

5.  Stems  of  gas-fixtures,  or  those  parts  which  carry  gas  for  more 
than  one  burner-nozzle,  must  be  the  following  sizes : 


When  Made  of 


Iron  Pipe,  cased. 

Brass  Pipe. 

6  or  under 

Not  smaller  than  J  in. 

Not  smaller  than  ^  in 

7  to  12  inclusive  
12  and  over                 .    .  . 

Not  smaller  than  f  in. 
2  in.  and  over. 

Not  smaller  than  ^  in. 

6.  All  keys  must  be  well  ground,  and  so  fitted  as  to  show  no 
leak  under  3  Ibs.,  mercury-gage  pressure,  when  the  keys  can  be 
turned  by  finger. 

7.  The  opening  in  all  globe  rings  must  be  a  snug  fit  against  the 
burner-nozzle,  and  must  flare  out  in  an  inverted-cone  shape,  so  that 
the  burner,  in  screwing  down,  will  not  strike  the  knife-edge  of  the 
flare,  but  hold  the  globe  ring  tight  by  binding  against  the  sides  of 
the  cone,  making  at  the  same  time  a  tight  joint  with  the  nozzle- 
threads. 

8.  The  company  reserves  the  right  to  take  fixtures  apart  at 
any  time,  and  to  refuse  to  pass  them  if  they  are  not  constructed 
in  accordance  with  good  workmanship. 

Note. — The  above  requirements  refer  to  combination  fixtures 
as  well  as  to  plain  gas-fixtures.  Where  there  are  good  reasons  for 
making  the  stems  of  combination  fixtures  supplying  less  than  six 
lights  of  smaller  size  than  J-in.  pipe,  the  matter  should  be  taken 
up  with  the  company  by  the  fixture  manufacturer. 

The  following  table  is  based  on  the  well-known  formula  for  the 
flow  of  gas  through  pipes.  The  friction,  and  therefore  the  pressure 
necessary  to  overcome  the  friction,  increases  with  the  quantity  of 
gas  that  goes  through,  and  as  the  aim  of  the  table  is  to  have  the  loss 
in  pressure  not  exceed  one-tenth  of  an  inch  water  pressure  in  30 
ft.,  the  size  of  the  pipe  increases  in  going  from  an  extremity  toward 
the  meter,  as  each  section  has  an  increasing  number  of  outlets  to 
supply.  The  quantity  of  gas  the  piping  may  be  called  on  to  pass 


240 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


through  is  stated  in  terms  of  f-in.  outlets,  instead  of  cubic  feet, 
outlets  being  used  as  a  unit  instead  of  burners,  because  at  the 
time  of  first  inspection  the  number  of  burners  may  not  be  defi- 
nitely determined.  In  designing  the  table,  each  f-in.  outlet  was 
assumed  as  requiring  a  supply  of  10  cu.  ft.  per  hour. 

TABLE  SHOWING  THE  CORRECT  SIZES  OF  HOUSE  PIPES  FOR  DIFFERENT 
LENGTHS  OF  PIPES  AND  NUMBERS  OF  OUTLETS. 


No.  of 
Outlets. 

Length  of  Pipe  in  Feet  for  Various  Diameters. 

I  in. 

*  in. 

I  in. 

1  in. 

U  in. 

11  in. 

2  in. 

2|  in. 

3  in. 

1 
2 
3 
4 
5 
6 
8 
10 
13 
15 
20 
25 
30 
35 
40 
45 
50 
65 
75 
100 
125 
150 
175 
200 
225 
250 

20 

30 
27 
12 

50 
50 
50 
50 
33 
24 
13 

70 
70 
70 
70 
70 
70 
50 
35 
21 
16 

100 
100 
100 
100 
100 
100 
100 
100 
60 
45 
27 
17 
12 

1,50 
150 
150 
150 
150 
150 
150 
150 
150 
120 
65 
42 
30 
22 
17 
13 

200 
200 
200 
200 
200 
200 
200 
200 
200 
200 
200 
175 
120 
90 
70 
55 
45 
27 
20 

300 
300 
300 
300 
300 
300 
300 
300 
300 
300 
300 
300 
300 
270 
210 
165 
135 
80 
60 
33 
22 
15 

400 
400 
400 
400 
400 
400 
400 
400 
400 
400 
400 
400 
400 
400 
400 
400 
330 
200 
150 
80 
50 
35 
28 
21 
17 
14 





I 

In  using  the  table  observe  the  following  rules: 

1.  No  house  riser  shall  be  less  than  f  in.     The  house  riser  is 
considered  to  extend  from  the  cellar  to  the  ceiling  of  the  first 
floor.     Above  the  ceiling  the  pipe  must  be  extended  of  the  same 
size  as  the  riser  until  the  first  branch  line  is  taken  oft0. 

2.  No  house  pipe  shall  be  less  than  f  in.     An  extension  to 
existing  piping  may  be  made  of  J-in.  pipe  to  supply  not  more 
than  one  outlet,  provided  said  pipe  is  not  over  6  ft.  long. 

•  3.  No  gas-range  shall  be  connected  with  a  smaller  pipe  than 
1  in.     No  pipe  laid  underground  shall  be  smaller  than  1J  in.     No 


HOUSE  PIPING.  241 

pipe  extending  outside  of  the  main  wall  of  a  building  shall  be  less 
than  |  in. 

4.  In  figuring  out  the  size  of  pipe,  always  start  at  the  extremi- 
ties of  the  system  and  work  towards  the  meter. 

5.  In  using  the  table,  the  lengths  of  pipe  to  be  used  in  each 
case  are  the  lengths  measured  from  one  branch  or  point  of  junc- 
tion to  another,  disregarding  elbows  or  turns.     Such  lengths  will 
be  hereafter  spoken  of  as  "  sections, "  and  are  ordinarily  of  but  one 
size  of  pipe,  as  no  change  in  size  of  pipe  may  be  made  other  than 
at  branches  or  outlets,  except  where  the  length  of  a  " section"  is 
greater  than  the  greatest  length  allowed  in  the  table  for  the  size 
of  pipe  required  by  the  outlets  supplied  by  the  " section."    For 
example,  if  a  section  supplying  two  outlets  is  33  ft.  long,  27  ft.  of 
this  could  be  \  in.  and  the  remaining  6  ft.  of  f  in. 

6.  If  any  outlet  is  larger  than  f  in.,  it  must  be  counted  as  more 
than  one,  in  accordance  with  the  schedule  below: 

Size  outlet;  diam.  inches $         f         1        HU        2        2$        3 

Outlets  in  table 2        4        7        11       16      28      44      64 

Gas-grates  count  as  follows:  a  24x30-in.  for  four  outlets,  and 
a  30x30-in.  for  six  outlets.  Gas-logs  count  as  one  outlet  for  every 
2  in.  in  length;  thus  a  24-in.  log  counts  as  twelve  outlets. 

7.  If  the  exact  number  of  outlets  given  cannot  be  found  in  the 
table,  take  the  next  larger  number.     For  example,  if  seventeen 
outlets  are  required,  work  with  the  next  larger  number  in  the 
table,  which  is  twenty. 

8.  For  any  given  number  of  outlets  do  not  use  a  smaller-sized 
pipe  than  the  smallest  size  that  contains  a  figure  in  the  table  for 
that  number  of  outlets.     Thus  to  feed  fifteen  outlets   no  smaller 
pipe  than  1  in.  may  be  used,  no  matter  how  short  the  "section" 
may  be. 

9.  Never  supply  gas  from  a  smaller  size  of  pipe  to  a  larger  one. 
If  we  have  25  outlets  to  be  supplied  through  300  feet. of  pipe,  and 
these  25  and  5  more,  making  30  in  all,  through  100  feet  of  pipe,  we 
should  find  by  the  table  that  30  outlets  through  100  feet  would 
require  2-inch  piping;  but  as  under  this  condition  a  2-inch  pipe 
would  be  supplying  a  2^-inch,  the  100-foot  section  must  be  made 
2|  inches.     This  does  not  apply  to  the  case  of  a  small  pipe  inside 
of  a  building  supplying  one  outside  of  the  main  wall  of  a  building 
made  large  on  account  of  the  conditions  of  outside  supply. 

PIPE-FITTING   SPECIFICATIONS. 

In  all  cases  of  repair  of  leaks  a  notice  giving  the  location  and 
extent  of  all  work  performed  shall  be  filed  with  the  building  com- 
missioner immediately  upon  completion  of  the  same. 


242 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


No  pipe  or  fitting  shall  be  covered  or  concealed  from  view  until 
approved  by  one  of  the  gas-fitting  inspectors  of  the  building  depart- 
ment, or  for  thirty  hours  after  notice  has  been  given  to  the  building 
commissioner. 

Pipes  shall  be  run  and  laid  to  avoid  any  strain  or  weight  on  the 
same,  except  that  of  the  fixtures. 

Outlets  for  fixtures  shall  be  securely  fastened;  all  outlets  not 
covered  by  fixtures  shall  be  left  capped,  and  the  number  of  burners 
for  each  outlet  shall  be  marked  on  the  builders'  plan. 

Pipes  laid  in  a  cold  or  damp  place  shall  be  properly  dripped, 
painted  with  two  coats  of  red  lead  and  boiled  oil,  or  covered  with 
felting  satisfactory  to  the  building  commissioner. 

Swing-brackets  shall  have  a  globe  or  guard  to  prevent  their 
burner  from  coming  in  contact  with  the  wall.  Bracket  outlets  shall 
be  at  least  2J  inches  from  window  or  door  casings. 

Stop-pins  to  cocks  shall  be  screwed  into  place. 

The  use  of  gas-fitters'  cement  is  prohibited  absolutely. 

Inside  services  shall  be  tested  by  the  fitter  who  received  the 
permit  to  connect  the  service  or  meter. 

There  shall  be  a  final  test  by  a  gas-fitter  of  all  fixtures  and  pipes 
by  a  column  of  mercury  raised  not  less  than  six  inches,  which  must 
stand  ten  minutes;  this  test  to  be  made  in  the  presence  of  one  of 
the  gas-fitting  inspectors  of  the  building  department;  the  gage  to 
be  made  of  glass  tubing  of  uniform  interior  diameter,  and  so  con- 
structed that  both  surfaces  of  the  mercury  will  be  exposed. 

All  gas-pipes  shall  be  of  wrought  iron  or  steel,  all  fittings  of 
malleable  iron,  and  all  meter  connections  of  lead  pipe  of  the  same 
size  as  the  riser,  except  where  meters  are  to  be  connected  with 
flanges. 

Brass  solder  nipples  shall  be  used  on  all  lead-meter  connections. 

Gas-pipes  of  iron  shall  be  run  in  accordance  with  the  following 
scale: 


Diameter, 
Inches. 

Length, 
Feet. 

No.  of  Burners. 

| 

26 

3 

I 

30 

6 

a 

50 

20 

1 

70 

35 

J| 

100 

60 

li 

150 

100 

2 

200 

200 

2J 

300 

300 

3 

450 

450 

3$ 

500 

600 

4 

600 

750 

HOUSE  PIPING. 


243 


pe   n, 


I 


I 


t 


~L 


I 
I 


244 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


When  brass  piping  is  used  on  the  outside  of  plastering  or  wood- 
work, it  shall  be  classed  as  fixtures. 

Outlets  and  risers  not  provided  with  fixtures  shall  be  properly 
capped. 


JJrtfifyrffut, 


Outlets  for  fixtures  shall  not  be  placed  under  tanks,  back  of 
doors,  or  within  three  feet  of  any  meter. 

Gas-burners  less  than  two  feet  from  a  plastered  ceiling,  or  less 
than  three  feet  from  overhead  woodwork,  shall  be  protected  by  a 


HOUSE  PIPING. 


245 


shield  satisfactory  to  the  building  commissioner.     In  first-class 
buildings  no  shields  will  be  required. 

Brass  tubing  used  for  arms  or  fixtures  shall  be  at  least  No.  18 
standard  gage,  with  full  thread.     All  threads  shall  screw  in  at  least 


ffifffif 


Section,. 


A  of  an  inch.  Rope  or  square  tubing  shall  be  brazed  or  soldered 
into  fittings  and  distributors,  or  have  a  nipple  brazed  into  the 
tubing. 

Cast  fittings  such  as  cocks,  swing-joints,  double  centers,  and 
nozzles  shall  be  standard  fittings,  except  for  factory  use,  where 


246  AMERICAN  GAS-ENGINEERING  PRACTICE. 

extra-heavy  or  mill  fittings  shall  be  used.  The  plugs  of  all  cocks 
must  be  ground  to  a  smooth  and  true  surface  for  their  entire  length, 
be  free  from  sand-holes,  have  not  less  than  f-inch  bearing  on  cast 
fittings  and  H  of  an  inch  on  turned  fittings,  have  two  flat  sides  on 
the  end  for  the  washer,  and  have  two  nuts  instead  of  a  tail-screw. 
Stems  of  fixtures  of  two  lights  or  more  each  shall  be  not  less  than 
i  of  an  inch  iron-pipe  size.  L-burner  cocks  shall  not  be  used  at  the 
end  of  chandelier  arms  except  in  stores,  churches,  theaters,  halls, 
and  places  of  assembly  or  public  resort. 

Outlets  for  gas-ranges  shall  have  a  diameter  not  less  than  one 
inch,  and  all  gas-ranges  and  heaters  shall  have  a  cock  on  the  service- 
pipe.  Ranges  and  heaters  must  be  connected  with  right  and  left 
couplings,  except  in  fireplace  work,  where  brass  unions  may  be  used. 

Pipes  shall  be  laid  above  timbers,  unless  otherwise  permitted  by 
the  building  commissioner. 

No  second-hand  pipe  shall  be  put  into  use  in  any  building  with- 
out the  written  permission  of  the  building  commissioner. 

Drops  or  outlets  less  than  j  of  an  inch  in  diameter  shall  not  be 
left  more  than  j  of  an  inch  below  plastering,  center-piece,  or  wood- 
work, and  other  outlets  shall  not  project  more  than  f  of  an  inch 
beyond  plastering  or  woodwork. 

Fastening-boards  shall  not  be  cut  away  to  accommodate  electric 
wires.  All  outlets  shall  be  fastened  according  to  the  diagrams 
on  page  245. 

Gas-pipes,  arms,  and  stem  of  fixtures  shall  be  of  the  kind  classed 
as  standard  pipe,  and  shall  weigh  according  to  the  following  table: 

Diam.  of  Pipe,  Pounds 

Inch.  per  Foot. 

i 0.24 

J 0.42 

| 0.56 

1 0.85 

J 1.12 

1   ' 1.67 

1J '.  2.24 

11 2.68 

2   3.61 

21 5.74 

3   7.54 

3J 9.00 

4 10.66 

No  gas-pipe  shall  be  laid  within  six  inches  of  an  electric  wire, 
except  where  the  electric  wire  is  an  insulated  conduit. 

Wherever  spark-lighting  or  self-lighting  burners  are  used  the 
mercury  test  shall  be  applied  to  the  cocks. 


HOUSE  PIPING. 


247 


GAS-ENGINES. 

(a)  Gas-engines  must  be  connected  to  service  from  which  no 
gas  for  illuminating  purposes  is  used. 

(6)  Exhaust-pipes  shall  be  run  to  roof  when  possible,  not  come 
in  contact  with  woodwork,  -and  be  properly  protected. 

(c)  Diaphragms  and  bags  must  be  on  the  same  floor  with  engine 
and  have  a  valve  governing  same. 

(d)  The  sizes  of  pipes  used  in  connecting  gas-engines  will  be  as 
follows: 


Horse- 
power. 

Feet  per 
Hour. 

Burners 

Diam., 
Inches. 

Length, 
Feet. 

Horse- 
Power. 

Feet  per 
Hour. 

Burners 

Diam., 
Inches. 

Length, 
Feet. 

1 

40 

10 

| 

50 

15 

600 

150 

2 

200 

2 

80 

20 

1 

50 

16 

640 

160 

2 

200 

3 

120  . 

30 

70 

17 

680 

170 

2 

200 

4 

160 

40 

1} 

100 

18 

720 

180 

2 

200 

5 

200 

50 

i| 

100 

19 

760 

190 

2 

200 

6 

240 

60 

if 

100 

20 

800 

200 

2 

200 

7 

280 

70 

if 

150 

21 

840 

210 

21 

300 

8 

320 

80 

if 

150 

22 

880 

220 

2f 

300 

9 

360 

90 

if 

150 

23 

920 

230 

2i 

300 

10 

400 

100 

M 

150 

24 

960 

240 

• 

300 

11 

440 

110 

2 

200 

25 

1000 

260 

2\ 

300 

12 

480 

120 

2 

200 

26 

1040 

260 

21 

300 

13 

520 

130 

2 

200 

27 

1080 

270 

21 

300 

14 

560 

140 

2 

2CO 

Gas  shall  not  be  turned  on  in  any  building  until  the  piping  and 
fixtures  have  been  approved  by  the  building  commissioner. 

Capacity  of  House  Piping. — The  following  is  given  in  the  report 
of  the  committee  on  research  of  the  American  Gaslight  Association: 


Diameter, 
Inches. 

Length  Allowed, 
Feet. 

No.  of  Burners. 

I 

20 

3 

30 

6 

I 

50 

20 

1 

70 

35 

11 

100 
150 

60 
100 

2 

200 

200 

2i 

300 

300 

3 

450 

450 

Allowing  six  feet  of  gas  per  hour  to  a  burner,  this  table  seems  to 
be  figured  for  gas  of  a  gravity  of  0.42  and  a  loss  of  pressure  of  0.1 


248 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


in.  within  thirty  feet.  The  following  will  show  the  capacity  of 
pipes  of  the  length  and  diameter  given  in  the  foregoing  for  gas 
having  a  specific  gravity  of  0.42,  0.55,  and  0.68,  the  loss  of  head  in 
each  case  being  0.1  inch  in  30  feet. 

TABLE  SHOWING  AMOUNT  OF  GAS  THAT  WILL  BE  DELIVERED  IN  ONE 
HOUR  THROUGH  PIPE  OF  GIVEN  SIZE  AND  LENGTH  WITH  A  LOSS  OF 
PRESSURE  OF  ONE  INCH  OF  WATER  IN  THREE  HUNDRED  FEET. 


Specific  gravity  i 

0  42 

0  55 

0.68 

of  gas           J 

Diameter  in 
Inches. 

Length  in 
Feet. 

Cubic  Feet 
per  Hour. 

Cubic  Feet 
per  Hour. 

Cubic  Feet 
per  Hour. 

| 

20 

18 

15.6 

14 

I 

30 

37 

32.2 

29 

• 

50 

101 

88 

80 

1 

70 

210 

180 

162 

li 

100 

360 

310 

280 

if 

150 

577 

500 

450 

2 

200 

1200 

1030 

930 

2i 

300 

2050 

1800 

1610 

3 

450 

3300 

2850 

2560 

Pipe  Cement. — The  following  " dopes"  are  in  common  use  for 
the  making  up  of  threaded  pipes  and  fittings: 

Where  oil  or  gas  or  vapors  are  used  under  pressure,  the  best 
mixture  is  equal  parts  of  white  lead,  red  lead,  coach-varnish,  and 
dryer.  Under  ordinary  conditions  there  may  be  used  either: 

Red  lead  and  graphite,  mixed  with  water  and  oil. 

Graphite  and  lard-oil. 

Raw  linseed-oil  (J)  and  Portland  cement  (§  by  volume). 

Asphaltum  and  varnish. 

Plumbago  and  linseed-oil. 

Fine  emery  and  white  lead.  . 

Aluminum  elastic  cement  and  linseed-oil. 

One  part  each  of  litharge,  red  lead,  and  white  lead,  mixed  with 
linseed-oil. 

Shellac  and  wood-alcohol. 

Cylinder-oil  and  graphite. 

White  lead  and  coal-tar. 

FLUXES  FOR   SOLDERING. 

Iron  to  steel :  Borax  and  sal-ammoniac. 

Tinned  iron :  Rosin  and  zinc  chloride. 

Copper  and  brass :  Sal-ammoniac  and  zinc  chloride. 

Lead  and  composition  pipe:  Rosin  and  sweet-oil. 

Zinc:  Zinc  chloride. 


CHAPTER  XVIII. 
APPLIANCES. 

A.    GAS  RANGES  AND  HEATERS. 

A  GAS-RANGE  having  four  top  burners  and  an  oven-burner  should 
never  be  connected  to  less  than  a  f-in.  supply-pipe.  If  the  run  is 
long  (see  Rules  for  House  Piping),  a  1-in.  pipe  is  better,  say  for  a 
distance  of  over  50  ft.  from  the  me.ter.  A  1-in.  pipe  is,  however, 
better  practice,  as  this  admits  the  connection  of  a  supply-pipe  for  a 
water-heater.  The  meter  should  not  be  smaller  than  a  5-light. 
The  maximum  capacity  of  a  range  of  this  character  is  supposed  to 
be  about  60  cu.  ft.  per  hour. 

Efficiency. — The  following  is  given  by  the  gas  education  trus- 
tees of  the  American  Gaslight  Association  as  a  comparative  test 
of  the  efficiency  of  gas-ranges.  The  comparative  efficiency  of  the 
top  burners  of  various  samples  of  gas-stoves  may  be  tested  by 
determining  the  length  of  time  and  the  amount  of  gas  required  to 
heat  a  definite  quantity  of  water  from  the  temperature  of,  say,  60° 
F.  to  the  boiling-point.  The  same  kettle  should  be  used  throughout 
the  test,  and  the  weight  of  water  employed,  its  temperature  at  the 
start,  the  exact  time  at  which  it  begins  to  boil,  and  the  amount  of 
gas  consumed  being  accurately  determined  in  each  case. 

The  efficiency  of  the  oven  may  be  tested  by  determining  the 
time  and  amount  of  gas  required  to  bring  each  oven  up  to  a  baking 
heat,  to  be  determined  with  an  oven  thermometer,  and  then  to  bake 
a  definite  weight  of  either  bread  or  biscuit.  The  dough  must  be 
ready  to  put  into  the  oven  as  soon  as  the  required  heat  is  attained, 
so  that  no  gas  is  wasted  while  waiting  for  the  dough  to  be  gotten 
ready,  since  any  delay  of  this  kind  would  spoil  the  test.  Each  oven 
should  also  be  tested  for  evenness  of  distribution  of  the  heat  through- 
out its  whole  interior.  This  can  be  done  by  placing  pieces  of  white 
writing-paper  (unglazed)  in  different  parts  of  the  oven  and  noticing 
the  extent  to  which  the  different  pieces  are  browned  when  the  oven 
is  hot  enough  to  bake,  The  more  nearly  they  approach  the  same 

249 


250  AMERICAN  GAS-ENGINEERING  PRACTICE. 

color  the  more  uniform  is  the  distribution  of  heat  throughout  the 
oven  and  the  better  will  it  bake.  As  a  rule,  the  ovens  that  show 
good  efficiency  by  the  baking  test  will  also  show  a  uniform  distribu- 
tion of  the  heat. 

Burners. — Atmospheric  burners  in  stoves  may  be  classed  in  the 
main  as  ring  burners  with  drilled  holes,  radial  or  star  burners  with 
drilled  holes,  ring  burners  with  slits  sawed  in  them,  and  star  burners 
with  sawed  slits.  Annular  slit -ring  burners  and  serrated  disk  or 
cap  burners  are  occasionally  found,  but  the  drilled  or  sawed  burners 
are  most  commonly  used  in  the  best  type  of  stoves.  Other  things 
being  equal,  such  as  the  same  gas  and  air  mixture,  shape  and  weight 
of  metal,  etc.,  the  drilled-ring  burners  are  much  more  efficient  than 
the  ring-burners  with  slits  and  are  moreover  freer  from  stoppage 
and  easier  to  clean.  Next  to  the  drilled-ring  burners  come  the 
drilled  radial  burners,  after  which  follow  the  sawed  ring  and  sawed 
radial,  their  sequence  showing  the  order  of  efficiency. 

The  advantage  possessed  by  the  ring  burners  is  evident  to  the 
writer  because  of  a  certain  amount  of  regenerative  heat  and  also  a 
more  equal  flow  of  air  to  support  combustion.  By  regenerative 
heat  is  meant  that  a  certain  amount  of  the  radiant  heat  of  the 
burner  is  utilized  in  bringing  up  the  gas  to  the  point  of  combus- 
tion prior  to  ignition  and  thereby  permitting  less  gas  to  pass  the 
flame  area  consumed. 

Great  care  should  be  taken  in  the  proper  adjustment  of  air- 
mixers,  the  best  test  of  which  is  the  color  (an  electric  blue)  of  the 
flame  issuing  from  the  burner.  A  lack  of  sufficient  air  will  enor- 
mously reduce  the  economy  and  efficiency  of  the  burners,  besides 
causing  the  burner  to  clog  up  and  flash  back. 

This  flashing  back  is  caused,  as  a  rule,  either  by  improper 
design  of  the  burner,  a  preponderance  of  gas,  or  insufficient  air, 
due  either  to  bad  regulation  or  stoppage.  In  many  Bunsen 
burners,  brass  gauze,  or  netting,  is  used,  both  to  promote  the  more 
intimate  union  of  the  gas  and  air  and,  through  radiation,  to  lower 
the  temperature  of  the  gas  below  the  point  of  ignition  prior  to  its 
exit  from  the  burner.  This  gauze,  or  netting,  occasionally  becomes 
foul  and,  by  its  failure  to  supply  sufficient  air  or  by  the  increase 
of  heat  due  to  its  failure  to  radiate  on  account  of  this  insulation, 
causes  flashing  back  and  premature  explosion. 

In  an  ordinary  atmospheric  burner  the  quantity  of  air  in  the 
mixture  generally  depends  upon  two  conditions:  first,  the  size  of 
the  air-inlet,  and  second,  the  velocity  of  the  gas,  which  draws  in 
the  air  by  an  aspirator  action.  It  is,  therefore,  an  absolute  neces- 
sity in  all  conditions  where  atmospheric  burners  or  Bunsen  mix- 
'tures  are  used  to  have  an  ample  gas  pressure,  the  efficiency  of  the 
burner  increasing  to  some  measure  in  direct  ratio  to  the  initial 


APPLIANCES. 


251 


pressure.  Incandescent  mantles,  which  are  in  reality  devices  to 
convert  radiant  into  luminous  energy,  are  good  examples  of  this 
principle. 

FLOW  OF  GAS  IN  CUBIC  FEET  PER  HOUR  THROUGH  THIN  ORIFICES,  SUCH 
AS  AIR-MIXERS,  FOR  GAS-STOVES. 


Pressure  Equivalents. 

Diameter  of  Orifices,  Inches. 

Ounces 
per 
Sq.  In. 

Tenths  of 
Inches  of 
Water-head. 

Tenths  of 
Inches  of 
Mercury 
Column. 

ft; 

A 

& 

34* 

& 

A 

Cubic  Feet  Discharged  per  Hour. 

8 

0.59 

8.0 

12.0 

15 

20 

30 

45 

10 

0.74 

9.0 

13.0 

17 

23 

34 

51 

12 

0.89 

10.0 

15.0 

18 

25 

36 

56 

'0*8 

13.6 

1.00 

10.8 

16.0 

20 

27 

40 

61 

14 

1.03 

11.3 

17.0 

21 

28 

42 

63 

16 

1.18 

11.6 

17.5 

21.5 

29 

43 

65 

18 

1.34 

12.0 

18.0 

22 

30 

44 

67 

20 

1.48 

12.8 

19.0 

23 

32 

46 

72 

25 

1.86 

13.5 

20.4 

25 

34 

50 

76 

'i!e 

27 

2.00 

15.9 

21.0 

27 

38 

54 

86 

1.8 

30 

2.02 

16.4 

24.5 

31 

41 

62 

92 

2.4 

41 

3 

18.0 

27.5 

34 

46 

68 

105 

3.2 

54 

4 

21.6 

32.0 

41 

54 

82 

122 

4.0 

68 

5 

24.0 

35.5 

46 

60 

92 

135 

4.8 

81 

6 

26.4 

39.5 

51 

66 

102 

148 

5.6 

65 

7 

28.4 

42.5 

54 

71 

108 

160 

6.4 

109 

8 

30.0 

45.0 

57  . 

75 

114 

169 

7.2 

122 

9 

31.0 

47.0 

61 

78 

122 

176 

8.0 

137 

10 

32.4 

48.5 

64 

81 

128 

182 

8.8 

150 

11 

33.0 

51.0 

68 

85 

138 

191 

9.6 

163' 

12 

37.2 

55.0 

71 

93 

142 

209 

10.4 

177 

13 

38.8 

58.0 

74 

97 

148 

218 

11.2 

190 

14 

40.4 

60.5 

77 

101 

154 

227 

12.0 

204 

15 

42.0 

63.0 

80 

105 

160 

236 

12.8 

218 

16 

43.0 

65.0 

82 

108 

164 

243 

13.6 

231 

17 

44.0 

66.0 

84 

110 

168 

247 

14.4 

245 

18 

45.6 

67.0 

87 

114 

174 

255 

15.2 

258 

19 

47.0 

70.0 

90 

117 

180 

263 

16.0 

274 

20 

48.0 

72.0 

92 

120 

184 

270 

Piping.— The  gas-range  having  4  top  burners  and  an  oven- 
burner  should  never  be  connected  to  the  meter  by  less  than  a  f-in. 
pipe  and  this  should  only  be  in  instances  where  the  run  is  50  ft. 
or  under,  1-in.  pipe  being  used  for  a  greater  distance.  This  calcu- 
lation, based  on  gas  having  a  specific  gravity  of  0.7,  would  show  a 
loss  in  pressure  of  about  0.1  in.,  which,  under  average  conditions, 
should  be  the  maximum  loss  advisable. 


252  AMERICAN  GAS-ENGINEERING  PRACTICE. 

A  gas-range  of  the  average  type  should  invariably  be  connected 
to  a  5-light  meter,  a  3-light  meter,  while  under  most  conditions 
having  the  capacity  for  the  passage  of  the  requisite  gas,  entailing 
too  great  a  loss  of  pressure.  The  author's  tests  show  that  a  loss 
of  pressure  through  a  3-light  meter  due  to  maximum  demand  of 
gas-range  averages  0.4  in. 

Heat  Insulation. — The  consensus  of  opinion  seems  to  be  that 
the  asbestos  heat  insulating  lining  supplies  greater  economy  than 
the  dead  air-space  of  gas-ranges,  although  this  would  probably  not 
be  true  theoretically.  In  practice  the  dead  air-space  is  impossi- 
ble of  realization  and  the  practical  loss  of  radiant  heat  is  greater; 
moreover,  the  asbestos-lined  oven  seems  to  have  its  heat  more 
evenly  distributed.  The  following  table,  compiled  by  Prof.  C.  L. 
Norton,  shows  the  protection  afforded  by  insulating  linings: 

A  steam-pipe  heated  to  385°  F.  shows  an  outside  temperature  of 

356°  covered  with  asbestos-paper  -^  in.  thick. 

Oon°  t  (  ( (  (  (  it         JL    f (  ( c 

302°       "          "          "  "     &  " 

2fifi°        il          ll  ll  il      i   ' '       ' ( 

J.  C.  Bertsch  is  authority  for  the  statement  that  the  transmis- 
sion of  heat  per  square  foot  of  surface  per  minute  through  a  dead 
air-space  1  in.  in  thickness  is  8  B.t.u.,  while  that  of  asbestos-paper 
1  in.  thick  is  3J  B.t.u.  He  moreover  states  that  the  dead  air- 
space, properly  speaking,  does  not  exist  in  the  oven  of  the  modern 
gas-range,  it  being  impossible  to  join  the  metal  sheets  so  closely 
as  to  prevent  circulation;  under  these  conditions  air  has  little 
or  no  properties  insulating  value.  Therefore  asbestos-boards  & 
to  i  in.  in  thickness  are  the  more  effective  and  economical  and 
moreover  tend  to  form  a  dead  air-space  with  the  outside  metal 
sheet. 

What  is  commonly  known  as  sweating  in  the  oven  of  a  gas- 
range  is  largely  due  to  the  hydrogen  in  the  gas  burning  to  aqueous 
vapor  and  being  condensed  against  the  walls  of  the  oven.  It  may 
be  the  result  of  improper  ventilation,  which  may  be  remedied  by 
the  rather  uneconomical  expedient  of  increasing  the  size  of  the 
flue-outlet ;  or  the  air-passage  may  have  become  closed  and  steam 
from  any  article  being  cooked  may  itself  have  been  condensed; 
it  may  also  be  caused  by  the  cold  walls  of  the  oven,  due  to  im- 
proper lining,  in  which  case  the  lining  should  be  examined  and 
replaced.  The  ventilation  may  be  responsible,  as  before  suggested, 
by  reason  of  the  insufficient  draught,  the  air-ports  in  the  range 
having  become  stopped  and  failing  to  carry  off  the  aqueous  vapor 
formed  by  the  combustion  of  gas.  In  many  instances,  however, 


APPLIANCES.  253 

it  is  simply  the  shock  of  the  first  gases  of  combustion  coming  in 
contact  with  the  cold  sides  of  the  range,  and  this  can  be  overcome 
by  allowing  a  more  lengthy  burning  of  the  pilot-light,  or  by  leav- 
ing the  oven-doors  open  for  a  minute  or  so  after  lighting  the  range. 
At  this  point  it  may  also  be  stated  that  ranges  when  not  in  use  for 
any  length  of  time  should  be  left  with  their  doors  partly  open,  or, 
better  still,  unhinged  and  entirely  removed,  as  the  metal  of  the 
range  has  a  tendency  to  condense  upon  itself  moisture  from  the 
atmosphere,  which  in  a  closed  oven  is  most  destructive  to  the 
sheets  and  linings. 

Gas  Consumed. — The  consumption  of  gas-range  ovens  varies 
naturally  with  the  dimensions  of  the  oven.  With  650  to  700  B.t.u. 
gas  and  2-in.  water  pressure  the  burners  should  be  able  to  deliver 
45  cu.  ft.  of  gas  per  hour  to  a  16-in.  oven  and  50  cu.  ft.  with  an 
18-in.  oven  (double  burner).  Under  average  burning  conditions 
the  oven  can  doubtless  be  heated  with  a  less  quantity  of  gas,  but 
a  certain  latitude  in  heating  power  should  be  placed  at  the  dis- 
posal of  the  cook,  for  various  articles  of  food  vary  in  the  quantity 
of  heat  required  and  the  period  of  time  within  which  the  heat 
should  be  delivered  and  cooking  be  completed. 

In  the  same  way  single-top  burners  should  have  a  capacity  of 
10  cu.  ft.  per  hour,  while  double  burners  should  have  some  15  to 
18  cu.  ft.  per  hour,  the  consumption  being  a  matter  of  optional 
and  local  regulation.  The  grate  should  be  situated  at  least  1.5  in. 
above  the  burner,  or  high  enough  to  prevent  the  impinging  of  the 
flame-cone  upon  the  bottom  of  the  cooking- vessel,  because  such 
vessels  have  a  tendency  to  lower  the  flame  temperature,  thereby 
preventing  complete  combustion.  The  burners  may  be  kept  ad- 
justed by  keeping  tight  the  set-screw  on  the  shutter  of  the  air- 
mixer  after  proper  regulation  has  once  been  made.  It  is  necessary 
to  keep  the  drilled  holes  thoroughly  cleansed  and  free  from  carbon 
deposits;  this  may  be  accomplished  in  most  instances  by  a  fort- 
nightly washing  in  sal-ammoniac. 

Baking.— The  burning  of  bread  as  well  as  other  food  may  be 
due  to  placing  it  in  the  oven  too  soon  after  lighting;  the  oven  is 
not  then  hot  enough  to  radiate  much  heat  and  the  heat  comes  from 
the  direction  of  the  flames  only.  Burning  of  bread  may  be  due 
al  >3  to  the  use  of  pans  of  great  depth  for  baking,  their  deep  sides 
depriving  the  upper  portion  of  their  contents  from  its  neces- 
sary quota  of  heat.  It  may,  of  course,  be  caused  by  defective  con- 
struction of  the  oven,  which  in  this  day  of  gas-range  competition 
is  extremely  unusual.  Defective  regulation,  insufficient  insulation 
of  the  oven-bottom,  etc.,  may  also  be  contributory  causes.  Care 
should  be  taken  that  all  the  drilled  holes  in  the  burners  are  clear 
and  free  from  stoppage  and  that  the  flame  produced  is  of  a  proper 


254  AMERICAN  GAS-ENGINEERING  PRACTICE. 

color  and  forms  with  the  air-mixture  a  jet  in  the  shape  of  a  per- 
fectly symmetrical  cone.  There  is  no  economy  in  placing  food  in 
the  oven  before  it  attains  the  proper  heat,  which  under  usual 
conditions  is  approximately  four  minutes.  This  period  of  prepara- 
tion permits  the  walls  and  linings  of  the  range  to  heat  up  and  the 
atmosphere  of  the  range  to  obtain  the  temperature  requisite  to 
efficient  service.  This  is  especially  necessary  with  a  gas-range, 
because  the  intense  heat  is  localized  immediately  beneath  the  oven, 
usually  within  3  in.  under  the  bottom  of  the  bread,  whereas,  with 
the  ordinary  coal-range,  the  oven  is  more  or  less  insulated  from 
direct  heat,  but  is  heated  by  the  products  of  combustion,  all  parts 
equally  and  practically  simultaneously. 

In  extreme  cases  a  covered  baking-pan  with  a  ventilator  may 
be  used;  this  ventilator  should  remain  closed  until  the  bread  is 
nearly  baked.  This  cover  should  be  removed  at  from  two  to  three 
minutes  before  taking  the  bread  from  the  oven,  which  period  is 
usually  sufficient  to  properly  brown  it.  During  this  final  period 
the  heat  should  be  increased  to  the  maximum  capacity  of  the 
burner. 

The  rule,  to  preheat  the  oven,  should  be  invariable,  and  it  is 
usually  best  to  accomplish  this  by  using  the  maximum  capacity  of 
the  oven-burner,  after  which  the  flames  may  be  somewhat  reduced 
until  a  slow,  even  heat  is  secured.  As  before  mentioned,  the  tem- 
perature is  again  increased  to  maximum  during  the  "browning" 
period.  The  temperature  necessary  in  ovens,  of  course,  varies 
directly  with  the  food  to  be  cooked,  pastries,  etc.,  requiring  intense 
quick  heat,  while  other  food  requires  slow,  even  temperature. 

Gas-ranges  when  leaving  the  factory  are  generally  regulated 
for  the  average  pressure  in  the  town  in  which  they  are  to  be  in- 
stalled. In  every  town,  however,  the  district  or  local  pressure 
varies  widely.  It  is  occasionally  necessary  to  change  this  rating 
on  the  part  of  the  range,  which  is  done  either  by  supplying  a  dif- 
ferent nozzle  or  tip,  these  being  furnished  by  the  range-makers 
and  located  in  the  gas-inlet  of  the  burner.  Gas-ranges  cannot 
be  expected  to  operate  efficiently  under  a  greater  variation  than 
that  of  1.8  to  3.5  in.,  2  to  2.5  in.  obtaining  the  highest  efficiency. 
Should  the  district  pressure  vary  between  greater  limits  than 
these,  a  proper  governor  should  be  placed  either  upon  the  house 
service  or  directly  before  entering  the  gas-range  itself. 

Essentials. — A  few  of  the  essentials  to  be  observed  in  the 
selection  of  a  gas-range  by  any  gas  company  are: 

1.  Removable  burners  to  facilitate  cleaning. 

2.  Snugly  fitting  air-shutters,  convenient  to  adjust  and  fitted 

with  set-screws  to  retain  the  adjustment. 


APPLIANCES.  255 

3.  Removable  linings  for  facilitating  repairing. 

4.  Sufficient  weight  of  castings  to  prevent  breakage  in  mov- 

ing and  mechanical  strength,  such  as  unusual  strength  on 
the  part  of  hinges,  brackets,  and  all  castings  subject  to 
strain. 

5.  Distribution  of  heat  in  the  oven. 

6.  Properly  set  burners,  their  position  being  located  so  as  to 

obtain  the  highest  efficiency  in  combustion. 

7.  Oven-burners,    evenly    drilled,    distributing   the   flame    in 

equal  cones  and  low  enough  not  to  impinge  the  flame 
upon  the  baffles  or  heat-distributors  over  the  bottoms. 

8.  Sufficient  flue-opening  to  prevent  smothering  the  burners, 

to  remove  aqueous  vapors  from  the  oven,  and  to  furnish 
ventilation  for  steam. 

9.  Sufficient  air-ports  to  supply  ventilation  to  the  above  flues. 

10.  Linings  of  sufficient  thickness,  say  not  less  than  22  or  24 

B.  &  S.  gage,  so  as  to  prevent  rusting  out  in  a  reasonable 
length  of  time. 

11.  Proper  construction  of  top  burner  to  prevent  leakage  in 

cemented  joints. 

The  quantity  of  heat  lost  by  radiation  in  gas-ranges  will  aver- 
age 20  to  25  per  cent. 

Combustion. — The  drilled  burner  has  now  been  almost  uni- 
versally adopted.  The  size  of  drill-holes  for  an  average  illuminat- 
ing-gas of  2-in.  pressure  will  average  for  the  top  burners  (single 
burners)  ^  in.  diameter.  For  the  top  burners  (double)  ^g-  in., 
except  in  the  case  of  double  top  burners  with  two  valves,  which 
have  drilled  holes  of  ^  in.;  even  burners  having  two  valves  will 
average  -^  in.  diameter  holes. 

The  following  excellent  description  of  the  inductor  or  aspirator 
in  a  gas-burner  is  given  by  P.  A.  Degener.  The  action  of  the 
inductor  of  an  atmospheric  gas-burner  depends  upon  the  friction 
of  the  moving  stream  of  gas  which  draws  in  air  around  it,  the 
kinetic  energy  of  the  gas  giving  power  to  bring  the  mixture  to 
the  outlet  of  the  burner.  The  two  essential  points  are:  to  com- 
bine the  velocity  and  force  of  the  gas-jet  with  the  largest  possible 
surface,  and  shape  the  inductive  body  in  such  a  way  that  the  in- 
coming air  will  be  forced  against  the  jet. 

Qas=range  Cocks. — Where  the  range  cock  is  used  it  should  in- 
variably be  of  the  lock -wing  removable-handle,  socket-head  type 
in  order  to  insure  the  proper  control  of  this  valve  and  to  prevent 
its  use  by  children  or  ignorant  persons. 

It  is  a  matter  of  history  that  ninety  per  cent,  of  the  gas-range 
accidents  which  have  occurred  have  been  through  a  meddling  with 


256  AMERICAN  GAS-ENGINEERING  PRACTICE. 

or  improper  use  of  this  cock,  with  the  result  that  its  service  has 
been  abandoned  by  at  least  half  of  the  gas  companies  of  this  country. 
After  gas-ranges  are  set  they  should  be  inspected  thoroughly  by  a 
competent  inspector,  who  will  note  pressure,  adjustment,  and  me- 
chanical correctness  of  fittings,  and  who  should  then  instruct  the 
consumer  in  the  use  of  the  appliance. 

As  it  may  occasionally  be  necessary  to  set  the  gas-ranges  or  gas- 
burning  appliance  in  districts  where  the  pressure  is  abnormally  low 
or  subject  to  very  considerable  fluctuation,  having  a  low  minimum 
sawed  burner  will  be  found  to  be  advantageous,  as  it  is  less  liable  to 
iiash  back  under  sudden  drops  of  either  pressure  or  candle-power. 

The  quality  of  gas  most  efficient  for  the  use  of  gas-ranges  and 
other  gas-burner  appliances  depends  entirely  upon  its  calorific 
value,  which  varies  in  the  case  of  coal-gas,  straight  water-gas,  or 
mixed  gas.  The  gas  should  have,  however,  a  value  of  about  650 
B.t.u.,  and  should  not  be  less  than  a  minimum  of  16  to  17  candles; 
for  coal-gas  18  candles  are  better,  20  candles  for  water-gas,  and  18 
candles  for  mixed  gas  (see  table  of  candle-power  compared  with 
calorific  value).  The  most  satisfactory  results  from  water-gas, 
however,  are  obtained  from  a  22-c.p.  gas;  with  this  gas,  while  it  is 
possible  to  adjust  aBunsen  mixture  at  1.5  in.  pressure,  the  most 
satisfactory  results  obtain  under  2.5  in.  pressure,  the  maximum 
permissible  being  about  3.5  in. 

Where  ranges  or  other  heating  appliances  are  used  adjacent  to 
walls,  such  walls  should  be  invariably  protected  by  sheet  asbestos- 
board. 

Testing  Ranges. — As  has  been  said,  under  very  widely  varying 
pressure  conditions,  or  rather  under  conditions  of  extreme  high  or 
low  pressure,  where  local  governors  may  be  deemed  inadvisable,  it 
may  sometimes  be  best  to  vary  the  size  of  the  nozzle  used  on  the 
gas-inlet  to  the  Bunsen  burners. 

These  nozzles  are  bored  or  drilled  according  to  the  B.  &  S.  or 
Morse  standard  drill  gages,  and  to  test  or  identify  their  sizes,  which 
run  usually  between  30  and  45,  an  internal-diameter  gage  is  used, 
as  shown  in  Fig.  63,  opposite.  It  should  always  be  among  the  tools 
of  every  fuel-appliance  or  repair  department. 

An  examination  into  the  standards  for  gas-ranges  maintained  by 
the  largest  fuel-supplying  companies  of  this  country  shows  about  the 
following  average: 

The  floor  test,  which  is  made  by  placing  a  black-bulb  chemical 
thermometer  upon  the  floor  immediately  beneath  the  oven  and 
just  below  the  center  of  the  range,  should  show  a  mean  tempera- 
ture of  about  120  deg.  Fah.  in  40  minutes  after  lighting. 

It  is  necessary  that  a  black-bulb  thermometer  be  used  in  order 
to  prevent  the  reflection  of  radiant  heat. 


APPLIANCES. 


257 


It  is  presumed  that  a  gas-range  oven  of  ordinarily  good  con- 
struction will  attain  a  baking  heat,  viz.,  about  400  deg.  Fah.,  with 
650  B.t.u.  gas  in  from  9  to  11  minutes  (pressure  from  1.5  to  2.0  in.). 

The  consumption  of  gas  during  this  period  of  time  (i.e.,  10 
minutes)  varies  from  4.5  cu.  ft.  with  air-jacketed,  sheet-iron  ranges 
to  11  cu.  ft.  with  "all  cast-iron  type." 

Very  few  makes  of  ranges,  from  a  standpoint  of  efficiency,  show 
identical  results,  those  of  low  efficiency  being  sometimes  com- 
pensated to  some  extent  by  points  of  durability,  strength,  etc. 


Bottom  of  Qauge 


FIG.  63. — Gage  for  Burner-holes. 

The  oven  test  is  made  by  perforating  the  side  of  the  oven  and 
inserting  a  700-deg.  Fah.  straight-tube  thermometer  through  an 
asbestos  saddle.  The  saddle  should  shield  the  thermometer  from 
contact  with  the  case  of  the  range,  and  the  saddle  and  thermometer 
when  inserted  should  completely  close  the  orifice. 

Range-ovens  should  be  so  constructed  and  ventilated  that  they 
will  become  evenly  heated  in  all  parts  after  the  burners  have  been 
lighted  for  ten  minutes.  Both  top  and  bottom  of  any  food  baked 
should  be  evenly  browned  and  upper  and  lower  racks  should  show 
uniform  results  and  identical  heat. 

Moreover,  the  center  of  the  oven  should  show  no  different  results 
from  its  extreme  edges,  a  test  for  even  heat  throughout  the  oven 
being  best  effected  by  placing  small  pieces  of  unglazed  paper  of 
equal  size  in  various  portions  of  the  oven  and  noting  the  degree  of 
equality  with  which  they  are  browned. 


258 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


The  floor  temperature  test  should  never  indicate  a  higher  heat 
than  1100  deg.  Fah.,  as  any  increase  over  this  may  become  danger- 
ous to  woodwork. 

A  number  of  companies  specify  an  air-space  of  not  less  than  1 
inch  in  the  bottom  construction  of  the  oven,  and  that  there  be  not 
less  than  3  inches  of  clear  air-space  between  the  bottom  of  the 
range  and  the  floor.  This  arrangement  gives  practically  no  floor 
temperature  at  all  and  should  produce  an  oven  of  high  efficiency. 

Where  asbestos  sheets  are  used,  the  construction  should  be  such 
(see  Fig.  64)  as  to  permit  their  being  readily  interchanged. 


oooooooooo 


I  <  > 

u t_ 


Asbestos 


Asbestos 

FIG.  64. — Asbestos  Gas-range  Lining. 

A  simple  test  for  determining  whether  a  range  oven  is  ready  for 
baking  consists  in  placing  an  ordinary  piece  of  white  writing-paper 
upon  the  lower  shelf;  in  the  case  of  bread  it  should  turn  dark  brown 
quickly;  for  cake  it  should  turn  golden  brown  when  placed  upon 
the  middle  shelf. 

Demonstrators  should  be  urged  to,  as  far  as  possible,  instruct 
consumers  in  the  method  of  boiling,  broiling,  etc.,  within  the  oven 
instead  of  upon  the  upper  burners.  It  is  possible,  in  fact,  to  exe- 
cute any  manner  of  cooking  within  the  oven  which  can  be  done 
upon  the  top  burners,  and  usually  much  more  efficiently  and  with 
better  culinary  result.  Demonstrators  and  canvassers  should  also 
urge  upon  the  consumer  the  absolute  necessity  of  cleanliness  in  the 
maintenance  of  a  range,  both  for  the  preservation  of  the  appliance 
and  the  obtaining  of  efficient  results. 

The  range  should  be  washed  at  least  twice  a  month  with  a  stiff 
brush  and  afterwards  by  a  cloth  with  warm  water  and  a  little  caustic 


APPLIANCES.  259 

soda.  The  casting  should  be  gone  over  while  the  parts  are  still 
warm.  All  loose  parts,  including  racks,  burners,  and  any  small  or 
movable  portion  of  the  range,  should  be  placed  within  the  soda 
water  and  permitted  to  soak,  after  which  the  whole  should  be  wiped 
off  with  a  soft  clean  cloth  and  the  burners  lighted  for  a  few  mo- 
ments after  reassembling  to  dissipate  any  possible  dampness  and 
prevent  rust. 

The  whole  should  then  be  gone  over  and  carefully  oiled  with  a 
rag  containing  machine-oil.  This  will  prevent  rust  and  is  infinitely 
preferable  to  any  form  of  stove-polish. 

A  set  of  specifications  gotten  out  by  one  of  the  leading  gas 
engineers  is  herewith  appended. 

Range  Specifications.  —  The  weight  of  a  16-in.  range  complete 
shall  not  be  less  than  150  Ibs.;  that  of  an  18-in.  range  not  less 
than  175  Ibs. 

Top  Burners, — To  consist  of  three  single,  one  giant,  and  one 
simmer  burner.     Giant  burner  to  be  the  left- 
hand  front  burner.     Simmer  burner  to  be  lo-  hed 
cated  back  of  the  front  burners  and  not  inside 
of  any  of  the  burners. 

To  be  separable  with  a  good  depth  of  bowl, 
with  a  well-fitting  joint, — construction  as  shown 
on  accompanying  drawing  preferred.    All  burn-  FIG.  64. — Gas-range 
ers  to  be  so  placed  that  they  can  be  lifted  out;        Top  Burner, 
no  bolts  to  be  used. 

Carrying-tube. — Top  burners  to  be  open  on  the  mixer  end  to 
admit  brush  for  cleaning.  Mixer  to  have  adjustable  shields  that 
can  be  made  rigid  when  required. 

Top  and  Oven  Mantles. — To  be  extra  heavy  f-in.  pipe  through- 
out. 

Gage  of  Metal. — In  the  body  and  linings  of  the  stove  to  be  No. 
24. 

Body  of  Stove. — To  have  dead  air-space  not  less  than  J  in. 
asbestos-lined. 

Pipe-collar. — To  take  4-in.  pipe,  and  to  be  located  on  rear  of 
range  top. 

Oven  Flame-plate. — The  oven  flame-plate  and  bottom  should 
be  of  not  less  than  20-gage  metal  with  center  braces.  (See  Fig. 
61.)  This  flame-plate  construction  is  preferred. 

Oven-burners. — To  be  two  long  drilled  burners,  open  at  mixer, 
and  to  admit  brush  for  cleaning. 

Pilot-light. — To  be  so  constructed  that  it  will  light  both  oven- 
burners,  and  the  flame  to  be  visible  from  the  outside  of  the  oven. 

Valves. — Ranges  to  have  "needle-valves  having  independent 
adjustable  apertures  with  needle-point  heads  that  can  be  easily 


260  AMERICAN  GAS-ENGINEERING  PRACTICE. 

moved  with  fingers  for  the  purpose  of  properly  adjusting  the  gas 
supply.  Needle-point  heads  to  be  covered  by  suitable  caps. 

Gas  Supply  to  Top  Burners. — To  be  taken  off  manifold  at  back 
before  supply  is  taken  for  oven-burners. 

Gas  supply  to  all  burners  should  rise. 

Not  less  than  3  in.  of  clear  air-space  to  be  provided  between 
bottom  of  range  and  floor. 

Doors. — To  be  drop  pattern  balanced  by  counterweight;  no 
catch  or  spring  to  be  used. 

Gas  Apertures. — To  be  drilled  to  allow  a  consumption  by  oven- 
burner  of  27  cu.  ft.  each.  Single-top  burners  to  be  12  cu.  ft. 
capacity,  giant  burners  18  cu.  ft.,  water-heater  burners  40  cu.  ft., 
measured  at  a  gas  pressure  of  1.2  in. 

B.     LIGHTING  APPLIANCES. 

Mantle  Burners. — Incandescent  gaslights  increase  in  candle- 
power  in  direct  ratio  with  the  pressure  of  the  gas  flow,  and  it  is 
the  experience  of  the  writer  that  they  cannot  be  successfully 
operated  under  less  pressure  than  1.8  in.  of  water. 

There  are  many  makes  of  these  lights,  the  best  of  which  should 
comply  with  the  following  specifications: 

First. — That  both  the  air-inlet  and  gas-inlet  be  capable  of  easy 
and  complete  regulation. 

Second. — That  the  parts  be  as  nearly  as  possible  interchange- 
able. 

Third. — That  the  mantles  burn  with  an  even  light  throughout 
their  entire  service,  and  be  of  satisfactory  longevity,  in  which 
latter  respect  the  aluminum-type  mantle  seems  to  take  preference 
over  those  supported  by  asbestos. 

The  gas-apertures  in  the  regulating-valves  of  these  burners  are 
exceedingly  small  and  easily  clogged.  It  should  therefore  be  a 
cardinal  rule  with  all  gas  companies  that  their  workmen  should 
carefully  examine  the  condition  of  the  fixtures  before  installing  a 
burner  or  replacing  a  mantle,  and  that  this  examination  should 
reveal  a  clear,  unimpeded  flow  of  gas  with  full  pressure  and  free- 
dom from  obstructions,  this  latter  being  caused,  as  a  rule,  by  con- 
densation in  the  pipes,  meter,  or  services,  and  which  can  generally 
be  removed  by  the  sudden  admission  of  compressed  air  from  a 
pump  to  the  proper  condensing-chamber. 

Candle=power  and  Heat  Value. — In  a  lecture  delivered  be- 
for  the  Institution  of  Gas  Engineers,  Prof.  V.  B.  Lewes  gave  the 
following  table  as  the  average  relation  between  candle-power  and 
calorific  value  as  determined  by  a  number  of  tests,  but  said  that 
the  results  in  any  particular  case  might  vary  5  per  cent,  either 
way  from  these,  and  even  with  this  qualification  exception  was 


APPLIANCES. 


261 


taken  to  the  figures  by  gome  gas  engineers.     They  stand,  how- 
ever, as  the  most  definite  statement  yet  published. 


Calorific  Value,  B.t.u.  per  Cubic  Foot. 

Candle-power. 

Coal-gas. 

Carburetted  Water-gas. 

Gross. 

Net. 

Gross. 

Net. 

12 

540 

480 

490 

452 

13 

560 

500 

510 

472 

14 

585 

522 

529 

489 

15 

610 

542 

547 

508 

16 

625 

562 

567 

527 

17 

647 

582 

587 

547 

IS 

670 

603 

607 

567 

19 

690 

622 

627 

587 

20 

712 

642 

647 

607 

As  a  result  of  work  done  in  the  University  of  Michigan,  Messrs. 
White,  Russell,  and  Traver  decided  that,  all  other  conditions  being 
the  same,  the  light  given  per  cubic  foot  of  gas,  when  consumed  in 
incandescent  burners,  was  proportionate  to  the  calorific  value  of 
the  gas,  and  increased  directly  at  the  rate  of  one  candle  per  each 
additional  four  calories  (or  15.87  B.t.u.). 

With  these  experiments  the  ordinary  C.  Welsbach  burner,  with 
Welsbach  mantles,  was  used,  the  air  and  gas  adjustment  of  the 
burner  being  such  as  to  obtain  the  maximum  of  light.  Prof.  V. 
B.  Lewes  claims,  however,  that  the  efficiency  of  the  gas  in  an 
incandescent  burner  depends  more  upon  the  flame  temperature 
than  upon  the  calorific  value,  and  cites  results  of  certain  experiments, 
showing  a  duty  of  from  19  to  20  candles  per  cubic  foot  from  blue 
water-gas  when  burned  in  a  certain  design  of  Argand  burner 
without  any  preadmixture  of  air. 

The  mantle  itself  never  attains  the  theoretical,  or  even  the 
actual,  temperature  of  the  flame,  so  for  all  practical  purposes  the 
efficiency  of  illuminating-gas  for  use  in  incandescent  burners  may 
be  stated  as  being  directly  proportional  to  the  calorific  value.  By 
the  calorific  or  heat  value  of  a  fuel  is  meant  the  total  number  of 
heat-units  which  may  be  developed  from  it  by  complete  combus- 
tion, the  comparison  being  per  cubic  foot.  The  calorific  value  of 
an  elementary  substance  can  only  be  obtained  by  experiment,  but 
that  of  compounds  is  simply  calculated  by  an  addition  of  the  sum 
of  the  known  heat  value  of  their  constituents. 

Caloric  Requirements  for  Incandescent  Lighting. — Man- 
tles can  be  made  to  give  their  full  lighting  power  with  low 


262  AMERICAN  GAS-ENGINEERING  PRACTICE. 

heat-unit  gas,  such  as  blue  water-gas,  which  runs  as  low  as  290 
B.t.u.  per  cubic  foot.  With  350  B.t.u.  blue  gas  a  first-class  80- 
candle-power  Welsbach  burner  will  give  its  full  lighting  power  on 
6J  feet  of  gas. 

There  is  always  a  peculiarity  to  be  noted  in  the  case  of  blue 
gases,  such,  as  was  found  with  the  80-c.p.  burner  just  cited.  The 
ordinary  American  Welsbach  No.  71  burner  consumes  about  4 
cubic  feet  of  600  B.t.u.  gas  to  give  its  full  lighting  power.  This 
same  burner,  which  should  theoretically  burn  7  to  8  cubic  feet 
of  300  B.t.u.  gas  to  give  the  same  effect,  burns  only  about  6^  to  6^ 
feet  to  do  so.  In  other  words,  the  efficiency  of  the  blue  gas  relative 
to  its  heating  power  is  greater  than  that  of  ordinary  illuminating-gas. 

Flat=flame  Burners. — The  principles  governing  the  efficient 
combustion  of  gas  for  the  direct  production  of  light  are  very  fully 
set  forth  in  King's  "Treatise  on  Coal-gas,"  from  which  the  following 
summary  has  been  taken:  "Since  the  light  given  by  a  gas-flame  is 
due  principally  to  the  raising  to  incandescence  of  particles  of  carbon 
set  free  by  reactions  occurring  in  the  flame,  to  obtain  the  maximum 
amount  of  light  it  is  necessary  that  the  gas  should  be  so  consumed 
as  to  secure  the  setting  free  in  the  flame  of  the  greatest  possible 
number  of  carbon  particles  and  the  raising  of  the  particles  to  the 
highest  possible  temperature.  These  two  conditions  can  only  be 
secured  by  the  proper  regulation  of  the  amount  of  air  supplied  to 
the  gas-producing  flame,  and  of  the  manner  in  which  the  air  is 
brought  into  contact  with  the  gas.  The  formation  of  the  carbon 
particles  being  due  to  decomposition  of  the  hydrocarbon  constitu- 
ents of  the  gas,  principally  by  effect  of  heat,  anything  which  tends 
to  cause  the  combustion  of  these  hydrocarbons  before  they  are 
sufficiently  heated  to  be  decomposed  reduces  the  amount  of  light 
given  by  the  flame  by  reducing  the  number  of  carbon  particles 
present  in  it.  And  since  the  amount  of  light  produced  by  any 
given  number  of  carbon  particles  increases  with  the  temperature  to 
which  they  are  raised,  anything  that  tends  to  lower  the  temperature 
of  the  flame  also  reduced  the  amount  of  light  given  by  it. 

"Any  admixture  or  intermingling  of  air  and  gas  reduces  the 
illuminating  power,  both  by  partially  consuming  the  hydrocarbons 
before  they  are  sufficiently  heated  to  be  decomposed,  and  so  reducing 
the  number  of  carbon  particles  in  the  flame,  ar.d  also  by  cooling  the 
flame.  Any  over-draught  by  which  an  excess  of  air  is  brought  into 
contact  with  the  flame  so  as  to  be  heated  by  it  reduces  the  illumi- 
nating power  by  cooling  the  flame.  To  secure  the  maximum 
amount  of  light  from  the  gas,  it  is  therefore  necessary  that  the  air 
should  be  brought  into  contact  with  the  gas  in  just  the  proper 
amount  required  for  its  complete  combustion,  and  in  such  a  way 
that  the  contact  takes  place  only  on  the  surface  of  the  flame.  With 


APPLIANCES.  263 

flat  flames  the  great  cause  of  intermingling  of  air  and  gas  and  of 
excess  rush  of  air  against  the  surface  of  the  flame  is  a  high  velocity 
of  exit  of  the  gas  from  the  burner-tip  into  the  atmosphere.  The 
velocity  of  exit  increases  rapidly  with  the  pressure  at  which  the  gas 
is  supplied  to  the  burner-tip.  It  is  therefore  essential  that  the 
pressure  at  the  tip  be  low.  With  an  Argand  burner  this  pressure 
can  be  reduced  to  practically  nothing,  but  with  flat-flame  burners 
a  certain  amount  of  pressure  is  necessary  to  develop  the  flame  to 
its  proper  shape,  this  being  especially  the  case  with  union  jet  (fish- 
tail) burners. 

"  Any  swirling  motion  in  the  gas  also  tends  to  produce  an  inter- 
mingling of  gas  and  air  as  well  as  a  disagreeable  noise,  and  therefore 
the  arrangement  of  the  burner  should  be  such  as  to  supply  the  gas 
to  the  points  of  ignition  in  an  even  flow  free  from  eddies  or  rotary 
motion.  To  insure  that  all  the  gas  shall  be  consumed  to  the  best 
advantage,  it  is  necessary  that  the  proper  proportions  between  the 
gas  and  air  supply  shall  exist  over  the  whole  surface  of  the  flame, 
and  therefore  that  the  gas  shall  be  supplied  in  equal  quantity  at 
all  the  points  of  ignition. 

"The  following  details  of  construction  have  been  adopted  to  put 
into  effect  the  principles  brought  out  above.  To  insure  the  existence 
of  a  low  pressure  at  the  burner-tip  the  improved  forms  of  flat-flame 
burners  are  provided  either  with  some  forms  of  governor,  which 
maintains  the  pressure  at  the  tip  constantly  at  the  proper  point,  no 
matter  how  much  the  pressure  on  the  piping  increases,  or  else  with 
a  '  check/  which  is  usually  a  metal,  steatite,  or  lava  disk  inserted  in 
the  burner  pillar  so  as  to  cut  off  any  flow  of  gas  to  the  tip  except 
through  a  hole  in  the  disk,  the  area  of  which  is  smaller  than  that  of 
the  opening  in  the  tip,  the  relation  between  the  area  of  the  opening 
in  the  check  and  that  of  the  opening  in  the  tip  varying  with  the 
pressure  at  which  the  burner  is  designed  to  be  used,  that  is,  the 
higher  the  pressure  the  smaller  the  hole  in  the  check  for  same-sized 
tip. 

"To  produce  a  steady,  even  flow  of  gas  without  any  swirling 
motion,  some  burners  have  placed  between  the  check  and  the  tip 
a  screen  of  fine  wire  gauze,  which  breaks  up  any  currents  and  ren- 
ders the  flow  of  gas  uniform  throughout  the  whole  area  of  the 
burner  pillar,  while  others  depend  upon  the  steadying  action  pro- 
duced by  the  large  area  of  the  burner  pillar  above  the  check  as 
compared  with  the  area  of  the  opening  in  the  tip. 

"To  secure  an  equal  supply  of  gas  to  all  parts  of  the  flame,  slit 
(batswing)  burners  are  made  with  what  is  called  a  hollow  top,  by 
means  of  which  the  slit  is  kept  at  the  same  depth  in  all  parts  instead 
of  being  much  thicker  at  the  top  than  at  the  sides,  as  it  would 
necessarily  be  if  the  top  of  the  tip  were  left  solid  instead  of  hollowed 


264  AMERICAN  GAS-ENGINEERING  PRACTICE. 

out  inside  to  conform  with  its  shape  outside.  The  effect  of  extra 
thickness  at  any  place  is  that  less  gas  passes  through  the  slit  at  the 
thick  place,  and  that  consequently  the  conditions  are  not  the  same 
at  all  parts  of  the  flame.  A  further  improvement  in  this  direction, 
introduced  in  some  burners,  consists  in  cutting  the  slit  with  a  cir- 
cular saw  applied  from  above  the  tip,  and  thus  making  it  curved  on 
the  bottom  instead  of  flat,  as  is  the  case  when  it  is  cut  by  sawing  in 
the  ordinary  way.  With  the  flat-bottom  slit  some  of  the  gas  issues 
at  right  angles  to  the  axis  of  the  burner,  only  to  be  folded  back  on 
the  upper  part  of  the  flame  by  the  upward  draught  of  air  caused  by 
the  heat  of  the  flame,  while  with  a  curved-bottom  slit  this  effect  is 
avoided,  as  the  gas  issues  in  a  direction  along  which  it  is  free  to 
travel  without  being  turned  aside,  and  the  flame  is  thus  kept  of 
more  even  thickness  throughout. 

"In  Snugg's  table-top  burners  the  effect  of  the  upward  rush  of 
air  in  increasing  the  thickness  of  the  lower  edges  of  the  flame  is  still 
further  guarded  against  by  forming  a  circular  ' table'  immediately 
under  the  top  of  the  tip,  the  projection  of  which  deflects  the  cur- 
rents of  air  and  prevents  them  from  rising  vertically  against  the 
flame." 

C.     INDUSTRIAL  APPLIANCES. 

Operation. — For  gas-furnaces  and  industrial  appliances  the 
air  pressure  should  have  a  minimum  of  one  pound  and  a  maximum 
of  two.  The  exact  air  pressure,  of  course,  depends  upon  the  ther- 
mal quality  of  the  gas,  it  being  necessary  to  obtain  the  exact 
ratio  between  the  two  for  complete  combustion. 

Flashing  back  in  all  forms  of  Bunsen  burners  is  caused  by  the 
flame  traveling  back  through  the  burner  to  the  issuing  gas-jet  and 
may  be  due  to  insufficient  velocity  of  exit  at  the  burner-head  of 
the  gas-air  mixture,  to  a  too  highly  heated  burner-head,  to  the  exit 
orifices  of  the  burner-head  being  too  small,  to  the  mixing-tube 
being  too  hot,  etc.;  it  may  be  overcome  by  increase  of  gas  pres- 
sure or  the  removal  of  the  mixer  to  a  further  distance  from  the 
heat  area.  It  is  sometimes  caused  by  the  faulty  design  of  the 
burner,  but  in  practice  more  often  by  the  clogging  of  the  burner 
or  air-hole  strainer,  thereby  reducing  the  gas  velocity,  as  before 
mentioned.  It  is  occasionally  remedied  by  the  intervention  of  one 
or  more  wire  screens  between  the  head  of  the  burner  and  the  air- 
intake.  This  acts  on  the  principle  of  the  Davy  lamp,  reducing  the 
temperature  of  the  gas  to  below  the  combustion-point.  An  angle 
bend  or  deflection  in  the  pipe  intervening  between  the  air-mixture 
and  burner  outlet  tends  to  prevent  flashing  back,  which  fact  is 
utilized  in  the  construction  of  the  Martin  incandescent  burner. 

A  test  made  by  the  Troy  Laundry  Machine  Co.  shows  a  saving 


APPLIANCES. 


265 


of  one-half  of  the  gas  consumed  by  admission  of  air  to  Bunsen 
burners  under  pressure,  as  against  the  use  of  atmospheric  burners. 

The  minimum  pressure  of  gas  for  gas-arcs  should  never  be  less 
than  2  in.,  3  in.  being  good  average.  The  maximum  of  low-pres- 
sure efficiency  is  usually  obtained  at  about  4.5  in.;  but  under  high- 
pressure  conditions  the  result  obtained  at  one  pound  per  sq.  in. 
pressure  practically  doubles  the  efficiency  of  the  appliance. 

Where  air  is  admitted  to  Bunsen  burners  under  considerable 
pressure  and  the  gas  and  air  are  brought  together  at  the  burner, 
there  is  a  chance,  due  usually  to  some  stoppage  in  the  burner,  of 
the  air  backing  up  into  the  meter  and  forming  there  an  explosive 
mixture.  To  prevent  this,  it  is  a  safeguard  to  place  a  free-swing- 
ing check-valve  on  installations  of  this  kind  between  the  burner 
and  the  meter. 

The  writer's  tests  of  efficiency  of  burners  under  stereotyping 
crucibles  and  linotype  machines  vary  between  60  and  70  per  cent. 
The  complete  combustion,  of  course,  depends  upon  the  chemical 
constituents  of  the  gas;  it  will  run,  however,  between  two  and 
three  times  the  gas  volume  in  general  practice. 

The  Bunsen  mixture  or  complete  combustion  of  gas  through 
the  preadmixing  of  air  is  best  observed  by  its  gradation  in  color. 
The  pure  gas  burns  a  yellow  flame;  the  preadmixture  of  air  is 
indicated  by  a  blue  cone,  an  increase  of  air  showing  green, 
which  in  excess  shades  down  almost  to  the  white  of  an  alcohol 
flame,  high  economy  in  the  admixture,  continuing  the  air  addition, 
stopping  just  short  of  the  flashing-back  point. 

The  writer's  data  show  the  highest  record  of  flame  tempera- 
ture obtained  from  a  Bunsen  flame  to  be  1950°  to  2000°  C. 

Consumption. — The  consumption  of  burners  used  in  various 
industrial  furnaces  and  processes  has  been  found  to  be  as  follows : 


Appliances. 

Average 
Consumption, 
Cu.  Ft.  per  Yr. 

Appliances. 

Average 
Consumption, 
Cu.  Ft.  per  Yr. 

Rivet-heaters  

300,000 

Braziers 

75000 

Meat-branding  machine. 

150,000 

Caldron  heaters  

120  000 

Hotel  range  

300,000 

Soldering  furnaces 

40000 

Tinning-bath. 

300  000 

Gas-arc  lamps 

24  000 

Linotype  machine  
Gas  forges  

50,000 
300,000 

Tailor-  iron  heaters  
Laundry  irons  

40,000 
18000 

Gas  bakery  ovens  

200,000 

Gas  manglers  

50000 

Gas  steam-tables  
Enameling  ovens 

200,000 
120  000 

Glue  pots  
Water-stills 

40,000 

Qf)  ooo 

Confectioners'      gas- 

Gas  broilers.  .  . 

50000 

stoves  

120,000 

Incubators.  .  .  . 

10000 

Popcorn    poppers     and 
peanut  roasters  

50,000 

Gas-engines    per   actual 
working  h.p  

60000 

266  AMERICAN  GAS-ENGINEERING  PRACTICE. 

Qas=engines. — In  order  to  find  the  size  of  meter  required  for  a 
gas-engine,  multiply  the  brake  horse-power  by  3.4+5  for  the  num- 
ber of  lights  of  meter. 

Exhaust-pipe. — From  1  to  5  horse-power  requires  a  1-in.  to 
IJ-in.  pipe;  above  that  size  the  diameter  of  the  pipe  should  equal 
D  =0.528  h.p.°-57,  or  about  0.528Xthe  square  root  of  the  horse- 
power. The  heat  of  the  exhaust-pipe  is  great  and  likely  to  burn 
wood  if  too  near.  Bends  of  6  in.  diam.  or  more  should  be  used  and 
no  elbows  or  T's  allowed.  Turn  the  outlet  of  the  pipe  to  look 
downward.  To  prevent  excessive  noise,  the  pipe  can  be  carried 
into  a  drain-pit  and  surrounded  with  stones  covered  over  with 
straw. 

Cooling-water. — About  5  gallons  of  water  per  horse-power  per 
hour  will  be  required  for  the  cylinder  if  the  water  be  taken  direct 
from  the  main.  If  hard  water  is  used,  a  handful  of  washing-soda 
should  be  used  in  the  tank  every  month. 

Circulating-tank. — About  20  or  30  gallons  per  h.p.  of  cooling- 
water  with  pipes  from  1  to  3  in.  diam.  are  necessary.  The  return- 
pipe  is  usually  a  little  larger  than  the  flow,  with  a  rise  of  at  least 
2  in.  per  foot  leading  to  the  tank  at  the  normal  water-level. 


PART  III. 

GENERAL   TECHNICAL  DATA. 


CHAPTER  XIX. 


PROPERTIES  OF  GASES. 


A.  Composition. 

B.  Volume. 

C.  Specific  Gravity. 

D.  Specific  Heat. 


E.  Calorific  Value. 

F.  Temperatures. 

G.  Heat  Data. 


A.  COMPOSITION  OF  GASES. 

Various  Gases. — The  following  table  is  given  by  Bates  as  the 

average  percentage  constitution  of  the  gases  named. 

AVERAGE  COMPOSITION  OF  GAS  (PER  CENT). 


Gases. 

CO2 

O 

CO 

N 

C2H4 

CH4 

H 

Flue  gas        (bituminous 
coal).    
Hoffman  coke-oven  gas.  . 
Producer-gas        (bitumi- 
nous coal)  

9.65 
1.41 

2.05 

8.55 
0.43 

0.30 

0.00 
6.49 

27.00 

81.80 
0.00 

55.30 

0.00 
2.04 

0.40 

0.00 
36.31 

2.50 

0.00 
33.32 

12  00 

Producer-gas  (anthracite 
coal)  

2  50 

0  30 

27  00 

57  00 

0  00 

1  20 

12  00 

Water-gas  

4  00 

0  50 

45  00 

2  00 

0  00 

3  50 

45  00 

Natural  gas  

0  00 

0  80 

0  60 

3  00 

1  00 

72  00 

22  00 

Coal-gas.  . 

0.30 

0.40 

0.60 

2  80 

4  30 

36  50 

48  10 

268  AMERICAN  GAS-ENGINEERING  PRACTICE 

The  following  table  is  credited  to  J.  M.  Morehead. 

APPROXIMATE  COMPOSITION  OF  ORDINARY  GASES. 


4 

g 

9 

. 

*i 

Gas. 

3 
o.o 

• 
I 

1 

-aj 

| 

•o 

jj 

1 

n 

5° 

1 

i 

o 

>> 

n 

1 

2 

PQ 

£ 

Water-gas  24  c.p.  .  . 

4.5 

13.0 

0.5 

29.0 

32.0 

16.0 

5.0 

720 

0.63 

Coal-gas   16  c.p.  .  .  . 

2.0 

5.5 

0.5 

11.5 

43.5 

35.0 

2.0 

610 

0.45 

Acetylene   (commer- 

cial) 

96  0 

1  0 

4  0 

1600 

0  92 

Flue  gas  

16.0 

4.5 

0.5 

79.0 

1.06 

Pintsch  gas  

0.5 

23.5 

0.5 

1.0 

18.5 

52.5 

3.5 

1100 

0.73 

Engine  exhaust.  .  .  . 

8.0 



17.0 

75.0 



1.04 

Producer-gas  
Natural  gas 

6.0 
2  0 

27 

0  1 

22.0 
1  0 

11.6 

3.6 

88  1 

58.0 
5  2 

150 
900 

0.89 
0  56 

Blue  water-gas. 

3  0 

43  25 

50  0 

0  5 

3  25 

350 

0  42 

20  7 

79.3 

1.00 

The  above  figures  are  given  as  an  average  of  those  which  ordi- 
narily obtain  in  the  best  practice.  Local  conditions  and  require- 
ments probably  will,  of  course,  vary  these  figures  in  individual 
instances. 

Properties. — Another  authority  compiles  the  following  char- 
acteristics of  gases  usually  met  with  in  metallurgical  calculations. 


CARBONIC   ACID    OR   CARBON   DIOXIDE. 

Formula CO2 

Composition  by  weight 73 . 7%  O,  27 . 3%  C 

Density  or  specific  gravity,  air=  1 1 . 529 

Lbs.  per  cubic  foot .116 

Cubic  feet  per  Ib 8 . 62 

Cubic  feet  air  necessary  to  consume  1  cu.  ft Non-cumbustible 

B.t.u.  per  cubic  foot Non-combustible 

Solubility :  Vols.  absorbed  in  1  vol.  water 1 .23 

ILLUMINANTS    OR   HEAVY   HYDROCARBONS. 

Formula 90%  C  H4 

Composition  by  weight 85.7%  C,  14.3%  H 

Density  or  specific  gravity,  air=  1 . 985 

Lbs.  per  cubic  foot .  074 

Cubic  feet  per  Ib 13 . 38 

Cubic  feet  air  necessary  to  consume  1  cu.  ft 14.34 

B.t.u.  per  cubic  foot 1675 

Solubility:  Vols.  absorbed  in  1  vol.  water .15 


PROPERTIES  OF  GASES.  269 

OXYGEN. 

Formula 0 

Composition  by  weight 100%  O 

Density  or  specific  gravity,  air=  1 1 . 105 

Lbs.  per  cubic  foot .084 

Cubic  feet  per  Ib 11 . 94 

Cubic  feet  air  necessary  to  consume  1  cu.  ft Non-combustible 

B.t.u.  per  cubic  foot Non-combustible 

Solubility:  Vols.  absorbed  in  1  vol.  water .028 

CARBONIC    OXIDE   OR   CARBON    MONOXIDE. 

Formula CO 

Composition  by  weight 42.9%  C,  57. 1%  O 

Density  or  specific  gravity,  air  =  1 .967 

Lbs.  per  cubic  foot .073 

Cubic  feet  per  Ib 13 . 57 

Cubic  feet  air  necessary  to  consume  1  cu.  ft 2.39 

B.t.u.  per  cubic  foot 341 

Solubility:  Vols.  absorbed  in  1  vol.  water.. .023 

HYDROGEN. 

Formula H 

Composition  by  weight 100%  H 

Density  or  specific  gravity,  air=  1 .069 

Lbs.  per  cubic  foot .006 

Cubic  feet  Ibs 189 . 23 

Cubic  feet  air  necessary  to  consume  1  cu.  ft 2.39 

B.t.u.  per  cubic  foot 345 

Solubility:  Vols.  absorbed  in  1  vol.  water .019 

METHANE    OR   MARSH   GAS. 

Formula CH4 

Composition  by  weight 75%  C,  25%  H 

Density  or  specific  gravity,  air=  1 . 556 

Lbs.  per  cubic  foot .0422 

Cubic  feet  per  Ib .  23 . 72 

Cubic  feet  air  necessary  to  consume  1  cu.  ft 9 . 56 

B.t.u.  per  cubic  foot 1065 

Solubility:  Vols.  absorbed  in  1  vol.  water .035 

NITROGEN. 

Formula N 

Composition  by  weight 100%  N 

Density  or  specific  gravity,  air=  1 .971 

Lbs.  per  cubic  foot .073 

Cubic  feet  per  Ib 13 . 57 

Cubic  feet  of  ah*  necessary  to  consume  1  cu.  ft Non-combustible 

B.t.u.  per  cubic  foot Non-combustible, 

Solubility:  Vols.  absorbed  in  1  vol.  water ,,,.,,  .01§ 


270 


AMERICAN   GAS-ENGINEERING  PRACTICE. 


ACETYLENE. 

Formula C2H2 

Composition  by  weight 93 . 3%  C,  7.7%  H 

Density  or  specific  gravity,  air  =  1 .  918 

Lbs.  per  cubic  foot .  069 

Cubic  feet  per  Ib 14 . 32 

Cubic  feet  air  necessary  to  consume  1  cu.  ft 11 .91 

B.t.u.  per  cubic  foot 1600 

Solubility:  Vols.  absorbed  in  1  vol.  water 1.11 

AIR. 

Formula Mixture  O  and  N 

Composition  by  weight. 77%  N,  23%  O 

Density  or  specific  gravity,  air=  1 1 .000 

Lbs.  per  cubic  foot .  076 

Cubic  feet  per  Ib 13.15 

Cubic  feet  air  necessary  to  consume  1  cu.  ft.  . Non-combustible 

B.t.u.  per  cubic  foot Non-combustible 

Solubility:  Vols.  absorbed  in  1  vol.  water .017 

SPECIFIC  GRAVITY,   WEIGHT,   AND   SOLUBILITY    IN  WATER   OF   VARIOUS 
GASES  AT  60°  FAHR.  AND  80  IN.  BAROMETER. 


Name. 


Hydrogen 

Light   carburetted  hydrogen 

Ammonia 

Carbonic  oxide 

Olefiant  gas 

Nitrogen 

Air 

Nitric  oxide 

Oxygen 

Sulphureted  hydrogen . 

Nitrous  oxide 

Carbonic  acid 

Sulphurous  acid 

Chlorine 

Bisulphide  of  carbon.  .  . 


Specific 

Gravity, 

Air  Equal 

1.000. 


0.0691 

0.559 

0.590 

0.967 

0.968 

0.9713 

.000 

.039 

.1056 

.1747 

.527 

.529 

2.247 

2.470 

2.640 


Weight  of 

a  Cu.  Ft. 

in  Pounds 

Avoir. 


0.00529997 

0.0428753 

0.045253 

0.0741689 

0.0742456 

0.07449871 

0.0767 

0.0796913 

0.08479952 

0.0900994i, 

0.1171209 

0.1172743 

0.1723449 

0.189449 

0.202488 


Weight  of 
a  Cu.  Ft. 
in  Grains. 


37.09 

300.12 

316.77 

519.18 

519.71 

521.49 

536.60 

557 . 83 

593.59 

630.69 

819.84 

820.92 

1206.41 

1326.14 

1417.41 


Number 

of  Cu.Ft. 

Equal  to 

1  Ib. 


188.68 

23.32 

22.09 

13.48 

13.46 

13.42 

13.03 

12.54 

11.79 

11.09 

8.53 

8.52 

5.80 

5.27 

4.93 


Solubility. 
100  Vols.  of 

Water 
Absorbed. 


1.93  vols 
3.91    " 
72,720 

2.43    " 

16.15    " 

1.48    " 

1.70    " 

Not  soluble 

2.99  vols 

323.26    " 

77.78    " 

100.20    " 

4276.60    " 

236.80    " 

Not  soluble 


PROPERTIES  OF  GASES. 


271 


B.  VOLUME  OF  GASES. 

Expansion  of  Gases. — According  to  Professor  Lineham,  "  two 
laws  govern  the  varying  volume  of  a  gas,  according  to  whether 
temperature  or  pressure  be  kept  constant.  The  first  law  of  gas 
expansion,  discovered  by  Boyle  in  1662  and  verified  by  Marriotte  in 
1676,  states  that  the  volume  of  a  given  portion  of  gas  varies  in- 
versely as  its  pressure  if  the  temperature  be  constant.  Shown  by 
symbols, 

V  varies  as  -^     and     PV=  a  constant. 


The  relation  of  P  and  V  is  shown  by  diagram  in  Fig.  66,  the 
ordinates  PPf  of  the  curve  representing  pressure  and  the  ab- 
scissaB  VV  corresponding  volumes,  a  temperature  t°  being  main- 


VOLUMES 

FIG.  66. — Relation  of  Volume  to  Pressure. 

tained.  Only  one  curve,  the  rectangular  hyperbola,  has  ordinate  X 
abscissa  constant  throughout,  and  that  is  the  form  of  the  curve 
AB.  Although  always  approaching  the  co-ordinates  OC,  OD,  it 
only  meets  them  at  infinity. 

Isothermals. — By  reason  of  equality  of  temperature,  AB  is 
also  known  as  the  isothermal  of  a  perfect  gas,  that  is,  of  a  gas  fol- 
lowing Boyle's  law  perfectly.  Marriotte's  tubes,  Fig.  67,  prove 
fairly  well  the  accuracy  of  this  law.  A  and  B  are  strong  glass 
tubes,  A  being  sealed  at  top,  level  with  mark  10,  and  C  is  a  stout 
though  flexible  rubber  tube.  Taking  the  first  position,  mercury 
is  poured  into  the  funnel  D  until  about  level  with  0,  and  a  final 
adjustment  made  by  moving  B  up  and  down.  A  portion  of  air, 
imprisoned  in  the  leg  A,  supports  a  pressure  of  one  atmosphere, 
D  being  open,  and  has  the  volume  of  10  in. 

Raise  B  until  the  mercury  reaches  35",  and  the  fluid  in  A  will 
have  risen  to  5".  The  difference  of  mercury  levels  is  now  30  in., 
representing  an  additional  pressure  of  one  atmosphere;  so  the  air 


272 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


now  supports  two  atmospheres  and  has  a  volume  of  5  in.,  or 
PXV  is  constant.  Intermediate  experiments  can  easily  be  ob- 
tained and  the  law  more  generally  proved.  The  so-called  per- 
manent gases  are  practically  perfect,  and  others  fairly  so,  if  meas- 
ured at  a  much  higher  temperature  than  that  of  liquefaction. 

The  second  law  of  gas  expansion  was  discovered  by  Charles  in 


7 

Je 

J 

— 

-   i 

6 

0 

1 

3,W 

"ft   ' 

JL 

A 

1 

i 

11 

- 

\ 

I 

3 

if 

/  /       \ 
v.    c,  J 

^ 

' 

/ 

32 ... 

o 


FIG.  67. — Apparatus  Illustrating 
Boyle's  Law. 


FIG.  68. — Relation  of  Volume  to 
Temperature. 


1787,  published  by  Dalton  in  1801,  and  by  Gay-Lussac  in  1802,  all 
independently.  The  last-named  completely  verified  the  law, 
which  states  that  the  increase  in  volume  of  a  given  portion  of  gas 
varies  directly  as  the  increasing  temperature,  if  the  pressure  be 
constant;  or,  if  Fbe  original  volume,  V\  the  increase,  V2  the  total 
volume  after  increase,  and  t°  the  rise  in  temperature. 


varies  as  t°    and 


Vat°, 


PROPERTIES  OF  GASES.  273 

a  being  the  coefficient  of  cubical  expansion.     V  and  a  are  constant 
and  t°  the  only  variable;  hence 


The  coefficients  of  linear  expansion  for  solids  vary  with  the 
substance,  as  do  also  their  cubical  coefficients  (being  three  times 
the  linear  ones);  but  all  gases  not  only  expand  regularly,  but  each 
to  the  same  amount,  increase  of  temperature  being  equal,  one 
coefficient  serving  for  all.  Between  32°  and  212°  the  total  expan- 

n  *^£\fi^ 
sion  is  0.3665F  or  =0.00204  for  each  degree:  figures  found 

loU 

by  Gay-Lussac,  expanding  the  air  in  an  air-thermometer,  the  bulb 
dipping  in  heated  water,  whose  temperature  was  taken  by  mercury- 
thermometer. 

Absolute  Zero  of  Temperature.  —  Let  AB,  Fig.  68,  be  an  air- 
thermometer  with  an  air-tight  piston  C,  and  the  volume  AC  be 
called  1,  the  temperature  being  32°.  Set  off  ordinate  CD  for  vol- 
ume at  32°,  and  FE  for  that  of  212°.  The  latter  will  be  1.3665, 
and  the  gradual  volumetric  increase  be  shown  by  the  straight  line 
DE.  Supposing  the  law  true  for  extreme  limits,  -line  DA  (a  pro- 
duction of  DE}  will  mark  out  the  volume  as  we  decrease  the  tem- 
perature, ultimately  meeting  AB  in  A.  Then  at  A  the  volume 
will  have  decreased  to  nothing,  and  all  the  heat  will  have  been 
taken  out  of  the  air.  Though  these  possibilities  are  absurd,  their 
supposition  enables  us  to  fix  a  zero-point  having  important  advan- 
tages in  thermo-  volumetric  calculations. 

To  find  A,  the  absolute  zero  of  temperature,  we  proceed  by 
similar  triangles  : 

AC    DG  DGXCD     180X1 

CD=GE    and     AC=    Tffl         =  =  492    ab°Ut> 


then 

A's  reading  =  492°-  32°  =460°  below  zero  F. 

Any  ordinary  temperature  F.  may,  then,  be  made  absolute  by 
adding  460,  and  while  t°  indicated  Fahrenheit  readings,  r  will  show 
absolute  readings. 

Note  that  Fig.  68  is  a  graphic  statement  of  Charles'  law,  AE 
being  an  isopiestic  or  line  of  constant  pressure,  and  AB  a  line  of 
constant  temperature. 

Combination  of  Boyle's  and  Charles'  Laws.  —  PV  is  invari- 
able for  any  particular  position  on  the  thermometric  scale;  but 


274 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


if  t°  be  raised,  the  value  of  PV  will  be  raised  also.  In  Fig.  68,  if 
P  be  kept  constant,  v  will  vary  as  i;  so  if  V  increases  at  the  same 
rate  as  t,  any  series  of  multiples  of  V  will  similarly  increase;  and 
as  P  would  be  such  a  multiplier  in  Fig.  68,  then 

PV  varies  as  t    and    PV=ct, 

which  is  strictly  general,  c  being  a  coefficient  depending  on  the  gas. 
Taking  one  pound  of  air  at  a  temperature  of  32°,  and  at  atmos- 
pheric pressure,  reckoning  in  Ibs.  per  sq.  ft.  and  in  cubic  feet, 
Regnault  found  by  experiment  that 

PV= 26,214= ct,    then    c= 


For  superheated  steam  c=85.5. 

The  above  formula  gives  P  or  V  at  any  temperature,  when  c  is 
known. 

Three  States  of  Matter. — These,  the  solid,  liquid,  and  gaseous, 
are  well  understood,  and  it  is  also  now  admitted  that  all  bodies 
are  capable  of  existence  in  each  case  successively,  though  not 
necessarily  at  the  normal  pressure  and  temperature.  Taking  one 
pound  of  any  substance  and  applying  the  specific  heat  due  to  its 
state,  its  temperature  rises  one  degree,  and  as  the  specific  heat  is 
approximately  regular  for  each  state,  practically  the  whole  heat 
is  registered  on  the  thermometer.  But  in  all  substances  two  crit- 
ical points  occur,  called  the  points  of  fusion  and  evaporation,  and 
known  respectively  in  case  of  water  as  the  'freezing-  and  boiling- 
points*;  at  these  points  additional  heat  is  absorbed  merely  to  do 
the  work  of  rearranging  the  molecules,  of  fusing  or  melting  on  the 
one  hand  and  of  evaporating  on  the  other  hand.  Such  'latent' 
heat  is  not  observable  on  the  thermometer  and  must,  therefore, 
be  otherwise  detected." 

SOME   OF  THE  MORE  COMMON   GASES. 


Gas. 

Sym- 
bol. 

Molec- 
ular 
Weight. 

Gas. 

Sym- 
bol. 

Molec- 
ular 
Weight. 

A             'a 

NHs 

17 

Nitrogen 

No 

28 

At              h  "  "     a' 

N9O 

44 

Br2 

160 

Nitric  oxide  

NO 

30 

Clo 

71 

Nitrous  anhydride. 

N9O-< 

76 

CO 

28 

Nitric  peroxide  

NO2 

46 

CO2 

44 

N2O4 

92 

Ethylene 

CoH* 

28 

32 

Ha 

2 

Sulphureted  hydrogen  .  .  . 

TT    0 

34 

Hydrogen  chloride  

HC1 
I2 

36.5 
254 

Sulphurous  anhydride.  .  .  . 
Sulphur  

s62 

S2 

64 
64 

Methane             

CH4 

16 

Water  

H2O 

18 

Hg 

200 

PROPERTIES  OF  GASES. 


275 


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270 


AMERICAN    GAS-ENGINEERING  PRACTICE. 


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PROPERTIES  OF  GASES. 


277 


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1 1C  >C  i 


278 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


The  tension  of  water-vapor  for  the  temperature  observed  must 
be  found  from  tables  containing  these  tensions  for  the  different 
temperatures,  such  as  the  following : 

TENSION   OF  AQUEOUS  VAPOR  IN   INCHES   OF  MERCURY. 


Tempera- 
ture, deg.  F. 

Inches  of 
Mercury. 

Tempera- 
ture, deg.  F. 

Inches  of 
Mercury. 

Tempera- 
ture, deg.  F. 

Inches  of 
Mercury. 

40 

0.247 

57 

0.465 

74 

0.840 

41 

.257 

58 

.482 

75 

.868 

42 

.267 

59 

.500 

76 

.897 

43 

.277 

60 

.518 

77 

.927 

44 

.288 

61 

.537 

78 

.958 

45 

.299 

62 

.556 

79 

.990 

46 

.311 

63 

.576 

80 

1.023 

47 

.323 

64 

.596 

81 

1.057 

48 

.335 

65 

.617 

82 

1.092 

49 

.348 

66 

.639 

83 

1.128 

50 

.361 

67 

.661 

84 

1.165 

51 

.374 

68 

.685 

85 

1.203 

52 

.388 

69 

.708 

86 

1.242 

53 

.403 

70 

.733 

87 

1.282 

54 

.418 

71 

.759 

88 

1.323 

55 

.433 

72 

.785 

89 

1.356 

56 

.449 

73 

.812 

90 

1.401 

TENSION   OF   AQUEOUS  VAPOR. 


Degrees 
Centigrade. 

Tension  in 
Millimeters 
of  Mercury. 

Degrees 
Centigrade. 

Tension  in 
Millimeters 
of  Mercury. 

Degrees 
Centigrade. 

Tension  in 
Millimeters 
of  Mercury. 

-20 

0.927 

+  2. 

5.302 

6.4 

7.193 

-10 

2.093 

+   2.2 

5.378 

6.6 

7.292 

2 

3.955 

+   2.4 

5.454 

6.8 

7.392 

-     .8 

4.016 

+  2.6 

5.530 

7. 

7.492 

-      .6 

4.078 

+   2.8 

5.608 

7.2 

7.595 

-      .4 

4.140 

+  3. 

5.687 

7.4 

7.699 

-      .2 

4.203 

+  3.2 

5.767 

7.6 

7.840 

— 

4.267 

+  3.4 

5.848 

7.8 

7.910 

-  o'.8 

4.331 

+  3.6 

5.930 

8. 

8.017 

-  0.6 

4.397 

3.8 

6.014 

8.2 

8.126 

-  0.4 

4.463 

4. 

6.097 

8.4 

8.236 

-  0.2 

4.531 

4.2 

6.183 

8.6 

8.347 

-  0. 

4.600 

4.4 

6.270 

8.8 

8.461 

+  0.2 

4.667 

4.6 

6.350 

9. 

8.574 

+  0.4 

4.733 

4.8 

6.445 

9.2 

8.690 

+  0.6 

4.801 

5. 

6.534 

9.4 

8.807 

+  0.8 

4.871 

5.2 

6.625 

9.6 

8.925 

+  1. 

4.940 

5.4 

6.717 

9.8 

9.045 

+  1.2 

5.011 

5.6 

6.810 

10. 

9.165 

+   1.4 

5.0  2 

5.8 

6.904 

10.2 

9.288 

+  1.6 

5.155 

6. 

6.998 

10.4 

9.412 

+  1.8 

5.228 

6.2 

7.095 

10.6 

9.537 

PROPERTIES  OF  GASES. 


279 


TENSION    OF   AQUEOUS   VAPOR—  Continued. 


Degrees 
Centigrade. 

Tension  in 
Millimeters 
of  Mercury. 

Degrees 
Centigrade. 

Tension  in 
Millimeters 
of  Mercury. 

Degrees 
Centigrade. 

Tension  in 
Millimeters 
of  Mercury. 

10.8 

9.665 

20.6 

18.047 

32. 

35.359 

11. 

9.792 

20.8 

18.271 

33. 

37.410 

11.2 

9.923 

21. 

18.495 

34. 

39.565 

11.4 

10.054 

21.2 

18.724 

35. 

41.827 

11.6 

10.187 

21.4 

18.954 

40. 

54.906 

11.8 

10.322 

21.6 

19.187 

45. 

71.391 

12. 

10.457 

21.8 

19.423 

50. 

91.982 

12.2 

10.596 

22. 

19.659 

55. 

117.478 

12.4 

10.734 

22.2 

19.901 

60. 

148.791 

12.6 

10.875 

22.4 

20.143 

65. 

186  .  945 

12.8 

10.919 

22.6 

20.389 

70. 

233.093 

13. 

11.162 

22.8 

20.639 

75. 

288.517 

13.2 

11.309 

23. 

20.888 

80. 

354.643 

13.4 

11.456 

23.2 

21  .  144 

85. 

433.041 

13.6 

11.605 

23.4 

21.400 

90. 

525.450 

13.8 

11.757 

23.6 

21.659 

95 

633.778 

14. 

11.908 

23.8 

21.921 

99. 

733.21 

14.2 

12.064 

24. 

22.184 

99.1 

738.5 

14.4 

12.220 

24.2 

22.453 

99.3 

741.16 

14.6 

12.378 

24.4 

22.723 

99.4 

743.83 

14.8 

12.538 

24.6 

22.996 

99.5 

746.5 

15. 

12.699 

24.8 

23.273 

99.6 

749.18 

15.2 

12.864 

25. 

23.550 

99.7 

751.87 

15.4 

13.029 

25.2 

23.834 

99.8 

754.57 

15.6 

13.197 

25.4 

24.119 

99.9 

757.28 

15.8 

13.366 

25.6 

24.406 

100. 

760. 

16. 

13.536 

25.8 

24.607 

100.1 

762.73 

16.2 

13.710 

26. 

24.988 

100.2 

765.46 

16.4 

13.885 

26.2 

25.288 

100.3 

768.20 

16.6 

14.062 

26.4 

25.88 

100.4 

771.95 

16.8 

14.241 

26.6 

25.891 

100.5 

773.71 

17. 

14.421 

26.8 

26.198 

100.6 

776.48 

17.2 

14.605 

27. 

26.505 

100.7 

779.26 

17.4 

14.790 

27.2 

26.820 

100.8 

782.04 

17.6 

14.977 

27.4 

27.136 

100.9 

784.83 

17.8 

15.167 

27.6 

27.455 

101. 

787.63 

18. 

15.357 

27.8 

.    27.778 

105. 

960.41 

18.2 

15.552 

28. 

28.101 

110. 

1075.37 

18.4 

15.747 

28.2 

28.433 

120. 

1491.28 

18.6 

15.945 

28.4 

28.765 

130. 

2030.28 

18.8 

16.145 

28.6 

29.101 

140. 

2717.63 

19. 

16.346 

28.8 

29.441 

150. 

3581.23 

19.2 

16.552 

29. 

29.782 

160. 

4651.62 

19.4 

16.758 

29.2 

30.131 

170. 

5961.66 

19.6 

16.967 

29.4 

30.479 

180 

7546.39 

19.8 

17.179 

29.6 

30.833 

190. 

9442.70 

20. 

17.391 

29.8 

31.190 

200. 

11688.96 

20.2 

17.608 

30. 

31.548 

220. 

17390. 

20.4 

17.826 

31. 

33.405 

224.7 

25 

atmos. 

280 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


The  following  tables  will  be  useful  in  calculating  the  flow  of 
gases  in  pipes  by  Pole's  formula  given  in  the  chapter  upon  mains. 


SQUARE  ROOT  OF  PRESSURE. 


Water, 
Inches. 

Square 
Root. 

Water, 
Inches. 

Square 
Root. 

Water, 
Inches. 

Square 
Root. 

0.1 

0.3162 

1.5 

1.2251 

2.8 

.6733 

0.2 

0.4472 

.6 

.2649 

2.9 

.7029 

0.3 

0  .  5477 

.7 

.3038 

3.0 

.7320 

0.4 

0  .  6324 

.8 

.3416 

3.1 

.7606 

0.5 

0.7071 

.9 

.3784 

3.2 

.7888 

0,6 

0.7745 

2.0 

.4142 

3.3 

.8165 

0.7 

0.8366 

2.1 

.4491 

3.4 

.8439 

0.8 

0.8944 

2.2 

.4832 

3.5 

.8708 

0.9 

0.9487 

2.3 

.5165 

3.6 

.8793 

1.0 

1.0000 

2.4 

.5491 

3.7 

.9235 

1.1 

1.0488 

2.5 

.5811 

3.8 

1.9493 

1.2 

1.0954 

2.6 

1.6123 

3.9 

1.9748 

1.3 

.1401 

2.7 

1.6431 

4.0 

2.0000 

1.4 

1.1832 

SQUARE   ROOT  OF  THE   SPECIFIC   GRAVITY   OF  GAS. 


Specific 
Gravity. 

Square 
Root. 

Specific 
Gravity. 

Square 
Root. 

Specific 
Gravity. 

Square 
Root. 

Specific 
Gravity. 

Square 
Root. 

0.350 

0.5916 

0.440 

0.6633 

0.530 

0.7280 

0.620 

0.7874 

.355 

.5958 

.445 

.6671 

.535 

.7314 

.625 

.7905 

.360 

.6000 

.450 

.6708 

.540 

.7348 

.630 

.7937 

.365 

.6041 

.455 

.6745 

.545 

.7382 

.635 

.7969 

.370 

.6083 

.460 

.6782 

.550 

.7416 

.640 

.8000 

.375 

.6124 

.465 

.6819 

.5£5 

.7449 

.645 

.8031 

.380 

.6164 

.470 

.6856 

.560 

.7483 

.650 

.8062 

.385 

.6205 

.475 

.6892 

.565 

.7517 

.655 

.8093 

.390 

.6245 

.480 

.6928 

.570 

.7549 

.660 

.8124 

.395 

.6285 

.485 

.6964 

.575 

.7583 

.665 

.8155 

.400 

.6325 

.490 

.7000 

.580 

.7616 

.670 

.8185 

.405 

.6364 

.495 

.7035 

.585 

.7648 

.675 

.8216 

.410 

.6403 

.500 

.7071 

.590 

.7681 

.680 

.8246 

.415 

.6442 

.505 

.7106 

.595 

.7713 

.685 

.8276 

.420 

.6481 

.510 

.7141 

.600 

.7746 

.690 

.8306 

.425 

.6519 

.515 

.7176 

.605 

.7778 

.695 

.8337 

.430 

.6557 

.520 

.7212 

.610 

.7810 

.700 

.8367 

.435 

.6595 

.525 

.7246 

.615 

.7842 

PROPERTIES  OF  GASES. 


281 


C.  SPECIFIC  GRAVITY. 

Specific  Gravity  Determination. — The  relative  weight  of 
gases  often  determines  the  character  of  their  constituents,  whether 
they  contain  much  or  little  heavy  hydrocarbons  or  the  proportion 
of  hydrogen.  Specific  gravity  is  also  one  of  the  factors  that  deter- 
mine the  rate  of  flow  through  pipes  and  occur  in  Pole's  formula. 
When  we  say  the  specific  gravity  of  simple  coal-gas  is  0.4,  we  mean 

o 


u 


FIG.  69. — Apparatus  for  Bunsen's     FIG.  70. — Wooden  Mercury  Trough  for 
Effusion  Test  of  the   Specific  Effusion  Test. 

Gravity  of  Gas. 

that  it  is  0.4  as  heavy  as  the  same  volume  of  air  under  like  con- 
ditions. The  gas  balances  of  Letheby  and  Dr.  F.  Lux  weigh  the 
gas  directly  and  thus  determine  its  gravity,  but  the  precautions 
and  corrections  are  too  refined  for  ordinary  works  operation.  The 
apparatus  devised  by  Professor  Bunsen  is  applicable,  however,  and 
accurate  as  well.  It  depends  upon  the  property  of  gases  by  which 
the  velocity  with  which  they  pass  through  a  small  orifice  depends 
upon  their  specific  gravity,  or,  more  exactly  stated,  the  densities 
of  two  gases  are  directly  proportional  to  the  squares  of  the  times 


282  AMERICAN  GAS-ENGINEERING  PRACTICE. 

required  for  equal  volumes  under  like  conditions  to  pass  through 
the  same  minute  orifice.  The  apparatus  is  herewith  illustrated  and 
is  in  two  parts,  the  glass  tube  for  the  gas  and  the  stand  for  the 
mercury  seal,  Figs.  69  and  70,  as  shown  by  J.  A.  Butterfield  in  his 
'work  on  the  Chemistry  of  Gas  Manufacture.  A  thick-walled  glass 
tube  has  one  end  hermetically  sealed  by  a  platinum-foil  diaphragm 
pierced  at  its  center  by  a  hole  about  -%fa  inch  diameter  and  fitting 
by  a  gas-tight  ground  joint  into  a  long  tube  B  about  0.75  in.  in- 
ternal diameter,  provided  with  a  stop-cock  C  and  an  internal  float 
D.  On  the  tube  a  level  line  K  is  scribed,  and  two  sets  of  double 
lines  &  in.  apart  on  the  float.  Mercury  is  then  poured  into  the 
top  receptacle  of  the  stand,  filling  the  stem  and  top  up  to  a  line 
on  the  glass  windows  in  its  side. 

The  apparatus  is  now  ready  for  a  test.  First  dry  the  tube  and 
float  thoroughly;  see  that  the  mercury  is  dry  and  clean,  and  fill  the 
tube  with  gas  which  has  been  dried  by  drawing  through  calcium 
chloride;  insert  the  open  end  of  the  tube  into  the  mercury-bath 
and  into  the  stem  of  the  stand  until  the  mark  K  coincides  with 
the  surface  of  the  mercury.  The  float,  which  has  been  inserted 
into  the  tube  previously,  will  float  upon  the  mercury,  filling  the 
lower  portion  of  the  tube,  and  rise  gradually  as  the  pressure  expels 
the  gas  through  the  opened  stop-cock  and  the  small  aperture  in 
the  platinum-foil  diaphragm.  For  more  accurate  observation  a 
telescope  is  placed  at  some  distance  on  a  level  with  the  mercury, 
and  as  the  float  appears  above  the  surface  of  the  mercury  the 
appearance,  of  the  black  scribe  lines  is  watched  for,  the  first  one 
being  a  warning,  and  as  the  second  one  gets  level  with  the  surface 
of  the  mercury  a  stop-watch  is  started;  when  the  second  of  the 
second  set  of  double  lines  is  seen,  the  watch  is  stopped  and  the 
time  elapsed  noted.  Dried  air  is  then  tested  in  the  same  manner. 
If  the  gas  required  t  minutes  and  the  air  t\  minutes  and  the  density 
of  air  be  taken  as  1,  we  would  then  have  the  proportion 

Sp.  gr.  gas_  t2 


from  which  the  specific  gravity  can  be  found  with  sufficient  accu- 
racy for  ordinary  industrial  purposes.  Several  observations  should 
be  made  of  each,  however,  and  the  mean  used  for  calculation. 

Schilling's  Apparatus.  —  Another  apparatus  resembling  the 
Bunsen  type  is  often  used  in  determining  the  specific  gravity  of  a 
gas.  It  is  known  as  the  Schilling  effusion  test,  using  the  apparatus 
shown  in  Fig.  71.  The  outer  vessel  contains  water  in  which 
is  immersed  the  inner  glass  tube,  weighted  at  its  lower  end  to 
keep  it  immersed  and  provided  at  its  upper  end  with  two  tubes, 


PROPERTIES  OF  GASES. 


283 


one  to  the  left  with  a  valve  and  the  upright  one  having  a  3-way 
valve  with  scale  having  the  positions  "vent,"  "off,"  and  "on" 
marked  upon  it.  The  tube  also  has  two  scribe  marks  encircling 
it.  The  vertical  tube  is  terminated  by  a  plati-  ^ 

num-foil  disk  perforated  by  a  minute  hole. 
The  tube  is  first  raised,  air  enters  through  the 
"vent"  position  of  the  cock,  which  is  then 
turned  to  "off",  the  tube  placed  on  the  bottom 
and  the  cock  turned  to  "  on,"  the  air  thus  being 
forced  through  the  perforation  in  the  platinum 
foil  by  the  head  of  water  outside.  When  the 
water-level  inside  rises  to  the  lower  scribe  mark 
a  stop-watch  is  started,  and  stopped  imme- 
diately when  the  water  reaches  the  upper  mark. 
The  tube  is  then  charged  through  the  side  valve 
with  the  gas  to  be  tested,  and  the  time  in  sec- 
onds noted  as  before.  Since  the  velocity  of 
gas  passing  through  such  an  orifice  is  propor- 
tional to  the  square  root  of  the  density,  the 
densities  vary  as  the  squares  of  the  times 
required  for  the  same  volume  to  pass  under 
like  conditions,  or,  if  the  gas  required  tg  or  120 
seconds  and  the  air  ta  or  180  seconds, 


Sp.gr.  gas  =tf 
Sp.gr.air=l     tf 


(120)2 


=  0.44. 


FIG.  71.— Schilling's 
Effusion  Test. 


Dr.  Letheby  devised  a  more  accurate  piece  of  apparatus  for  the 
same  purpose,  consisting  of  a  glass  globe  having  extensions  and 
valves  above  and  below.  The  upper  end,  as  shown  in  Fig.  72, 
is  terminated  by  a  tube  surmounted  by  a  small  gas-burner  and 
containing  a  sensitive  thermometer.  The  lower  end  is  attached 
to  a  gas-jet  and  gas  allowed  to  flow  through  until  all  the  air  is 
expelled,  when  the  cock  is  closed  and  the  upper  cock  an  instant 
later.  The  thermometer  is  then  read  and  the  globe  weighed 
complete  in  a  sensitive  balance  in  a  dry  atmosphere.  Previously 
it  had  been  weighed  when  filled  with  air  and  the  weight  of  air 
contained  corrected  to  60  deg.  F.  and  30  in.  barometric  pressure; 
suppose  it  to  have  been  31  grains.  Suppose  the  temperature  of 
the  gas  to  have  been  found  to  be  56  deg.  F.,  the  barometric 
pressure  30.3  in.,  and  its  weight,  over  the  weight  when  holding 
a  vacuum,  found  to  be  15  grains.  The  correction  for  tempera- 
ture and  pressure  is  0.98,  making  the  corrected  weight  of  the  gas 
14.7  at  60  deg.  and  30  in.  Then  14.7^31=0.47,  the  specific 
gravity  desired. 


284 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


The  volume  of  this  globe  can  be  readily  calculated  when  once 
the  weight  of  air  contained  is  accurately  determined.  Since  1  cu.  ft. 
of  moist  air  weighs  532.4  grains  and  of  dry  air  535.9  grains,  100 
cu.  in.  of  moist  air  will  weigh  30.81  grains, 
which  will  contain  0.336  grain  of  moisture, 
making  the  weight  of  100  cu.  in.  to  be  30.81  — 
0.336  =  30.474  grains.  Suppose  the  given  globe 
was  found  to  contain  30.964  grains  of  air  at 
60  deg.  and  30  in.;  divide  this  by  30.474  and 
the  resultant  volume  of  the  globe  will  be  100.5 
cu.  in.  As  found  in  the  test  the  globe  con- 
tained 15  grains  of  gas;  then  (15X100) -=-100.5  = 
14.92  grains  will  be  the  weight  of  gas  it  con- 
tained for  100  cu.  in.  capacity. 

Greville  Williams  described  a  method  for 
determining  the  specific  gravity  of  gas  in  the 
Transactions  of  the  Gas  Institute  for  1882. 
He  dries  the  gas  and  air  before  testing,  although 
this  is  not  essential  for  the  method.  Balances 
used  in  specific  gravity  determinations  must  be 
of  extreme  accuracy,  weighing  to  one-tenth  mil- 
ligram when  the  globe  need  not  be  over  400 
c.c.  capacity.  The  globe  is  not  exhausted  and 
temperature  and  barometer  corrections  are 
avoided  by  selecting  a  day  when  the  barometer 
is  steady  and  keeping  the  gas  and  air  at  the 
same  temperature  by  means  of  a  gas-stove. 
The  air  must  first  be  freed  from  CO2  and 
moisture  by  passing  through  KOH,  then  H2SC>4, 
then  soda-lime  and  calcium  chloride.  The  air 
is  drawn  through  the  globe  until  all  trace  of  other  gases  is 
removed,  indicated  by  the  globe  remaining  constant  in  weight, 
the  cocks  are  closed,  the  globe  carefully  wiped  with  clean 
chamois  leather  and  hung  by  platinum  wire  to  the  balance- 
arm,  balanced,  and  the  weight  noted;  after  hanging  5  minutes  the 
weight  is  noted  again.  The  gas  is  then  passed  through  the  globe 
for  an  hour,  after  first  being  dried  by  tubes  of  calcium  chloride) 
the  cocks  closed,  the  one  on  the  supply-pipe  end  first,  and  the 
globe  again  weighed.  Gas  may  be  thus  weighed  continuously,  as 
long  as  the  barometer  and  thermometer  remain  constant.  Some 
tests  on  hydrogen  showed  a  deviation  of  0.0014  from  its  theoret- 
ical gravity  of  0.0693.  Bunsen  obtained  a  value  of  0.079,  or  an 
error  of  0.01,  by  this  method. 

The  specific  gravity  can  now  be  calculated  by  this  formula: 

Vnt-P 


FIG.  72.—  Letheby 
Globe  for  Weigh- 
ing Gases. 


D= 


Vnt 


PROPERTIES  OF  GASES. 


285 


where  V=  capacity  of  globe  in  cubic  centimeters; 

P=  difference  between  the  weights  of  globe  with  air  and  with 

gas,  grammes; 

n= weight  of  1  c.c.  of  air  at  T  deg.  C.; 
D  =  specific  gravity  by  experiment. 

The  advantage  is,  of  course,  the  doing  away  with  producing  a 
vacuum  in  the  globe. 

Dr.  Lux  invented  a  balance  which  goes  by  his  name  and  is 
shown  in  Fig.  73.  The  globe  is  at  one  end  of  a  balance-arm,  the 


FIG.  73. — Lux  Gas-balance. 

gas  connections  dipping  into  mercury,  and  the  specific  gravity  is 
read  directly  on  the  scale  at  the  other  end,  uncorrected  for  atmos- 
pheric conditions.  Thus  air  will  be  1  on  the  scale,  hydrogen  at 
0.07,  etc.  The  corrections  to  be  made  are  for  pressure  and  tem- 
perature. For  every  millimeter  at  which  the  barometer  stands 
above  or  below  760  mm.  there  is  added  or  deducted  0.0007  from 
the  reading  on  the  scale.  For  every  degree  C.  at  which  the  ther- 
mometer is  above  or  below  15  deg.  C.  deduct  or  add  0.002  to  the 
scale  reading.  The  apparatus  requires  very  careful  adjustment, 
but  affords  a  ready  means  for  determining  specific  gravity. 

Specific  Gravity  of  Oils. — This  can  best  be  found  by  a  specific- 
gravity  bottle,  or  a  carefully  graduated  hydrometer,  the  oil  being 
either  at  60  deg.  F.  or  39.1  deg.  F.  Take  a  glass-stoppered  specific- 
gravity  bottle,  weigh  it,  fill  it  up  to  a  mark  with  recently  boiled 
distilled  water  at  60  deg.  or  39.1  deg.  F.,  weigh  again,  dry  with 
alcohol,  fill  to  the  mark  on  the  neck  with  the  spirit  or  oil  to  be 
tested  (at  60  deg.  or  39.1  deg.),  weigh  again.  Then  the  weight  of 
oil  divided  by  the  weight  of  the  water  will  equal  the  specific  grav- 
ity. The  coefficient  of  expansion  of  petroleum  oils  is  about  0.0036 
per  deg.  F.  or  0.0065  per  deg.  C.  To  find  the  weight  of  a  cubic 
foot  of  oil,  multiply  its  specific  gravity  by  62.425,  the  weight  of  a 
cubic  foot  of  water.  Oils  are  usually  tested  in  degrees  Baume, 


286 


AMERICAN   GAS-ENGINEERING  PRACTICE. 


the  following  table  therefore  being  useful  in  converting  Baume 
degrees  into  specific  gravity. 

CONVERSION   OF  HYDROMETER   DEGREES   INTO   SPECIFIC  GRAVITY. 


Degrees 
Baum6. 

Specific 
Gravity, 
Water  =  1.5. 

Pounds  per 
Gallon. 

Degrees 
Baum6. 

Specific 
Gravity, 
Water  =  1. 

Pounds  per 
Gallon. 

10 

1.0000 

8.33 

49 

0.7821 

6.52 

11 

.9929 

8.27 

50 

.7777 

6.48 

12 

.9859 

8.21 

51 

.7734 

6.44 

13 

.9790 

8.16 

52 

.7692 

6.41 

14 

.9722 

8.10 

53 

.7650 

6.37 

15 

.9655 

8.04 

54 

.7608 

6.34 

16 

.9589 

7.99 

55 

.7567 

6.30 

17 

.9523 

7.93 

56 

.7526 

6.27 

18 

.9459 

7.88 

57 

.7486 

6.24 

19 

.9335 

7.83 

58 

.7446 

6.20 

20 

.9333 

7.78 

59 

.7407 

6.17 

21 

.9271 

7.72 

60 

.7368 

6.14 

22 

.9210 

7.67 

61 

.7329 

6.11 

23 

.9150 

7.62 

62 

.7290 

6.07 

24 

.9090 

7.57 

63 

.7253 

6.04 

25 

.9032 

7.53 

64 

.7216 

6.01 

26 

.8974 

7.48 

65 

.7179 

5.98 

27 

.8917 

7.43 

66 

.7142 

5.95 

28 

.8860 

7.38 

67 

.7106 

5.92 

29 

.8805 

7.34 

68 

.7070 

5.89 

30 

.8750 

7.29 

69 

.7035 

5.86 

31 

.8695 

7.24 

70 

.7000 

5.83 

32 

.8641 

7.20 

71 

.6990 

5.80 

33 

.8588 

7.15 

72 

.6956 

5.78 

34 

.8536 

7.11 

73 

.6923 

5.75 

35 

.8484 

7.07 

74 

.6889 

5.72 

36 

.8433 

7.03 

75 

.6829 

5.69 

37 

.8383 

6.98 

76 

.6823 

5.66 

38 

.8333 

6.94 

77 

.6789 

5.63 

39 

.8284 

6.90 

78 

.6756 

5.60 

40 

.8235 

6.86 

79 

.6722 

5.58 

41 

.8187 

6.82 

80 

.6666 

5.55 

42 

.8139 

6.78 

81 

.6656 

5.52 

43 

.8092 

6.74 

82 

.6619 

5.50 

44 

.8045 

6.70 

83 

.6583 

5.48 

45 

.8000 

6.66 

84 

.6547 

5.45 

46 

.7954 

6.63 

85 

.6511 

5.42 

47 

.7909 

6.59 

90 

.6363 

5.30 

48 

.7865 

6.55 

95 

.6222 

5.18 

PROPERTIES  OF  GASES.  287 


D.  SPECIFIC  HEAT. 

Specific  Heat  Defined. — This  term  denotes  the  amount  of  heat, 
expressed  in  heat-units,  which  is  required  to  raise  by  1°  the  tem- 
perature of  unit  weight  of  a  substance.  Since  a  heat-unit  is  the 
amount  of  heat  required  to  raise  by  1°  the  temperature  of  unit 
weight  of  water,  the  specific  heat  of  a  substance  is  the  ratio  between 
the  amount  of  heat  needed  to  raise  by  1°  the  temperature  of  unit 
weight  of  the  substance  and  the  amount  of  heat  required  to  raise 
by  1°  the  temperature  of  unit  weight  of  water.  If  the  unit  of 
weight  is  the  pound  avoirdupois,  and  the  temperature  is  measured 
in  Fahrenheit  degrees,  the  specific  heat  is  expressed  in  British  ther- 
mal units,  while  if  the  unit  of  weight  is  the  kilogram,  and  the 
temperature  is  measured  in  centigrade  degrees,  the  specific  heat  is 
expressed  in  calories.  It  is  expressed  by  the  same  number  in  each 
case.  More  heat  is  required  to  raise  the  temperature  of  unit 
weight  of  water  a  given  amount  than  is  needed  to  raise  by  the 
same  amount  the  temperature  of  unit  weight  of  any  other  sub- 
stance, with  the  exception  of  hydrogen;  therefore,  with  this  excep- 
tion, the  specific  heats  of  all  substances  are  less  than  1. 

The  amount  of  heat  required  to  raise  by  1°  the  temperature  of 
a  body  which  is  free  to  expand,  or,  as  it  is  said,  is  kept  under 
constant  pressure,  is  not  the  same  as  the  amount  required  to  pro- 
duce the  same  change  in  temperature  in  the  body  if  it  is  kept  at 
a  constant  volume.  For  every  substance  there  are,  therefore,  two 
values  for  the  specific  heat,  one  for  constant  pressure  and  one  for 
constant  volume.  There  is  also  what  is  termed  specific  heat  by 
volume,  which  is  the  amount  of  heat,  expressed  in  heat-units, 
required  to  raise  by  1°  the  temperature  of  unit  volume  of  a  sub- 
stance. But  when  the  term  "specific  heat"  is  used  without  any 
qualification,  as  in  the  statement  "the  specific  heat  of  nitrogen  is 
0.244,"  it  refers  to  specific  heat  by  weight  and  at  constant  pres- 
sure. 

The  relative  illuminating  value  of  the  different  hydrocarbons 
contained  in  water-gas  has  been  stated  as  follows  when  the  gas  is 
tested  in  a  burner  consuming  it  at  5  cu.  ft.  per  hour: 

Benzene C6H6  349.0 

Ethane C2H6  35.0 

Ethylene C2H4  68.5 

Methane CH4  5.0 


288 


AMERICAN  GAS-ENGINEERING   PRACTICE 


CALCULATING   MEAN   SPECIFIC   HEAT  IN   A  GAS. 


Constituent. 

Per  Cent  by 
Volume. 

Weight  of 
1  Cu.  Ft. 
in  Pounds. 

Weight  of 
Constituent 
in  Pounds. 

Specific 
Heats. 

Sp.  H.  X 
Wt.XVol. 

Authority 
for  Value  of 
Sp.  H. 

Benzol.  .  .  . 
C2H4  
CO  

1.00 

3.75 
8.04 

0.20640 
0.07410 
0.7407 

0.20640 

0.27787 
0  .  59552 

.187 
.245 
.403 

0.2450 
0.3460 
0.8355 

Wullner. 

t  ( 

n 

H  

47.04 

0.00530 

0.24931 

.396 

0  .  3580 

Regnault 

CH4  

36.02 

0.04234 

1  .  52508 

.319 

2.0115 

Masson. 

CO,  
O  

N 

1.60 
0.39 
2.15 

0.11637 
0.08463 
0  07429 

0.18619 
0.03300 
0  16046 

.300 
.405 
1  405 

0.2420 
0.0464 
0  .  2255 

t  ( 
Regnault. 

100  00 

3  22383 

4  3099 

4.3099 
3.2283 = 


1.337,  the  value  of  the  mean  specific  heat  for  the  above  gas. 


TABLE   OF  MEAN  SPECIFIC  HEATS   AT  CONSTANT  PRESSURE. 
(In  B.t.u.  per  Pound.) 


Degrees 
Fahrenheit. 

Carbon 
Dioxide. 

Water- 
vapor. 

Nitrogen. 

Oxygen. 

212 

0.201 

0.446 

0.244 

0.214 

392 

0.210 

0.462 

0.249 

0.218 

572 

0.219 

0.478 

0.253 

0.222 

752 

0.227 

0.494 

0.257 

0.225 

932 

0.236 

0.510 

0.262 

0.229 

1112 

0.245 

0.526 

0.266 

0.233 

1292 

0.254 

0.541 

0.270 

0.237 

1472 

0.263 

0.557 

0.275 

0.241 

1652 

0.271 

0.573 

0.279 

0.244 

1832 

0.280 

0.589 

0.284 

0.248 

2012 

0.289 

0.605 

0.288 

0.252 

2192 

0.298 

0.621 

0.292 

0.256 

2372 

0.307 

0.637 

0.297 

0.260 

2552 

0.315 

0.652 

0.301 

0.264 

2732 

0.324 

0.668 

0.305 

0.267 

2912 

0.333 

0.684 

0.310 

0.271 

3092 

0.342 

0.700 

0.314 

0.275 

3272 

0.351 

0.716 

0.318 

0.279 

3452 

0.360 

0.732 

0.323 

0.282 

3632 

0.368 

0.748 

0.327 

0.286 

3812 

0.377 

0.764 

0.331 

0.290 

3992 

0.385  . 

0.780 

0.336 

0.294 

4172 

0.394 

0.796 

0.340 

0.298 

4352 

0.403 

0.812 

0.344 

0.301 

4532 

0.412 

0.828 

0.349 

0.305 

Inaccuracies  in  the  experimental  data  on  which  this  table  is 
based  render  it  useless  to  attempt  to  interpolate  more  closely 
than  to  ninety  degrees. 


PROPERTIES  OF  GASES. 


289 


SPECIFIC  HEATS  AT  CONSTANT  PRESSURE. 

Air 0.2375 

Oxygen 0.2175 

Hydrogen 3 . 4090 

Nitrogen 0 . 2438 

Carbon  dioxide,  CO2 0.2170 

Carbon  monoxide,  CO 0 . 2479 

Olefiant  gas  (ethylene),  C2H4 0.4040 

Marsh  gas  (methane),  CH, 0.5929 

Blast-furnace  gas 0 . 2280 

Chimney  gases  from  boilers 0 . 2400 

Steam,  superheated 0.4805 

"VOLUMETRIC"  SPECIFIC   HEATS. 

Air,  oxygen,  carbon  monoxide,  hydrogen,  and  nitrogen  =  0.019. 
Carbon  dioxide  and  marsh  gas  =  0.027. 
Producer  gas  =  0.019. 

Volumetric  specific  heat  is  the  quantity  of  heat  required  to  raise  the 
temperature  of  1  cubic  foot  1  degree  from  32°  to  33°  F. 

SPECIFIC   HEAT  OF  SOLIDS   AND   LIQUIDS. 
(Water  =  1.) 


Substance. 

Specific 
Heat. 

Substance. 

Specific 
Heat. 

Acetic  acid 

0  6589 

Lead 

0  0314 

Alcohol  (sp  gr  793) 

0  622 

Lime  burned  . 

0  217 

Aluminium 

0  2143 

Lithium  

0  9408 

Antim  ny  cast  

0  05077 

Magnesium  

0  2499 

Arsenic  

0  0814 

Manganese  

0.1217 

Beeswax  

0.45 

Marble,  white  

0  21585 

Benzine  

0  .  3952 

Mercury  

0  .  03332 

Birch 

0  48 

Nickel 

0  10863 

Bismuth 

0  03084 

Oil  olive 

0  3096 

Brass  . 

0  09391 

Oil  sweet 

0  31 

Brick,  common  
Brick  fire  

0.2 
0  22 

Oil  of  turpentine  
Palladium 

0.472 
0  05928 

Cadmium  

0  05669 

Phosphorus                  .    . 

0  18949 

Chalk,  white  

0.21485 

Pine  

0  65 

Charcoal,  animal,  calcined.  . 

0  26085 

Platinum  

0  03243 

Charcoal,  wood  

0.24111 

Potassium  

0  .  1606 

Clay  white   burned 

0  185 

Selenium 

0  07616 

Ccal.     

0  2777 

Silicon  crystallized 

0  1774 

Cobalt  

0  10696 

Silicon  f  u  sed 

0  175 

Copper 

0  09215 

Silver 

0  05701 

Diamond  c. 

0  14687 

Sodium  

0  2934 

Ether  

0  5207 

Spermaceti 

0  32 

Glass  

0  19768 

Steel 

0  1175 

Gold  

0  03244 

Sulphur 

0  20259 

Graphite  

0  20187 

Sulphuric  acid     .    ... 

0  222 

Ice  

0  504 

Tellurium  

0  4737 

Iodine 

0  05412 

Thallium 

0  0336 

Iron,  cast        

0  12983 

Tin 

0  05695 

Iron,  wrought  

0  11379 

Zinc  

0  09555 

290 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


SPECIFIC  HEAT  OF  GASES   AND  VAPORS. 


Specific  Heat 
of  Equal 
Weights. 

Specific  Heat 
of  Equal 
Volumes. 

Specific  Heat 
of  Constant 
Volumes. 

Simple 
Gases 

Air.  . 

0.2374 
0.2175 
0.2438 
3.4090 
0.1210 
0.0555 

0.2374 
0.2405 
0.2370 
0.2359 
0.2962 
0.3040 

0  .  1687 
0.1559 
0.1740 
2.4096 

Oxygen.  . 

Nitrogen  

Hydrogen  

Chlorine  

Biomine  

Compound 
gases 

Binoxide  of  nitrogen  

0.2315 
0.2450 
0.2163 
0.2432 
0.1553 
0.1845 
0.2262 
0.2317 
0.5083 
0.5929 
0.4040 

0.2406 
0.2370 
0.3307 
0.2857 
0.3414 
0.2333 
0.3447 
0.2406 
0.2966 
0.3277 
0.4106 

0.1768 
0.1714 

0.1246 
0.4683 

Carbonic  oxide 

Carbonic  acid 

Sulphureted  hydrogen  
Sulphurous  an  ydride  

Hydrochloric  acid  

Nitrous  oxide  

Nitric  oxide  

Ammonia 

Marsh  gas 

Olefiant  gas  (ethylene)  

Vapors 

Water  (steam)  

0.4805 
0.4810 
0.1567 
0.4534 
0.5061 
0.1570 
0.3754 
0.4125 

0.2984 
1.2296 
0.6461 
0.7171 
2.3776 
0.4140 
1.0114 
0.8244 

0.3337 
0.3411 

0.3200 

Ether  

Chloroform 

Alcohol 

Turpentine 

Bisulphide  of  carbon  
Benzole                  .  .  . 

The  following  figures  are  given  by  D.  K.  Clark  in  his  treatise: 


Substance. 

Specific  Heat. 

Substance. 

Specific 
Heat. 

Ice  

0.504 

Brickwork,  masonry.  .  .  . 

0.200 

Water  at  32°  F 

1  000 

Coal    

0  2411 

Gaseous  steam 

0  475 

Anthracite  

0  2017 

Saturated  steam 

0  305 

Oak  wood  

0  570 

Mercury 

0.0333 

Fir  wood  . 

0  650 

Sulphuric  ether  
Alcohol  

(0.715)0.5200 
0  .  6588 

Oxygen     (constant    wt. 
and  vol.)  

0.1559 

Lead  

0.0314 

Air  (const,  pres.)  

0.2377 

Gold  

0.0324 

Air  (con  <l  .  wt.  and  vol.). 

0.1688 

Tin  

0.0566 

Nitrogen  (const,  wt.  and 

Silver 

0.0570 

vol.)  

0  .  1740 

Brass 

0  0939 

Hydrogen     (const,     wt. 

Copper 

0.0951 

and  vol.)  

2  .  4096 

Zinc 

0  .  0956 

Carbonic    oxide    (const. 

Nickel                    

0  .  1086 

wt.  and  vol.)  

0  .  1768 

Wrought  iron  

0.1138  to  0.1255 

Carbonic  acid  (const,  wt. 

Steel 

0  1165  toO  1185 

and  vol.)  

0  1714 

Cast  iron  

0  .  1298 

PROPERTIES  OF  GASES. 


291 


E.  CALORIFIC  VALUE. 

Calculating  Calorific  Power. — Since  results  are  stated  in  B.t.u. 
per  cu.  ft.  of  the  gas  investigated,  and  the  analysis  usually  gives 
percentage  by  volume,  it  is  often  convenient  to  use  the  volume 
values  for  the  calorific  power  of  the  constituents  of  a  complex  gas. 
Thomas  B.  Stillman  in  his  "  Engineering  Chemistry,"  p.  259,  gives 
the  following  values,  which  are  here  tabulated  for  more  conve- 
nient reference. 


Gas. 

Calories  per 
Kilogram. 

B.t.u.  per 
Pound. 

B.t.u.  per 
Cubic  Foot, 
0°  C.,  760  mm. 

H  hydrogen 

34,500 

62,100 

348 

CO  carbonic  oxide 

2,487 

4476 

349 

CH    methane 

13,245 

23,851 

1  065 

CaHz  acetylene  

11,925 

21,465 

1  555 

C2H    ethylene          

11,900 

21,440 

1  673 

C2H6  ethane             

12,350 

22,230 

1  858 

Illuminants  of  gas     

2000 

CoHa,  propane.  . 

12,028 

21,650 

2,654 

C..HR,  propvlene.  .                      .... 

11,900 

21,420 

2,509 

C  HHI  butane 

11,850 

21  330 

3  477 

C'H^,  penfane  

11,770 

21,186 

4,250 

C6Hj    sextane                               ... 

11,620 

20,916 

5012 

C6H6  benzene                            .... 

10,250 

18,450 

4010 

C10H8  naphthalene                    .... 

9,620 

17,316 

6  176 

Combustion  is  generally  affected  through  the  addition  of  air  to 
combustible  gases,  the  composition  of  air  being: 


Per  Cent  by 
Weight. 

Per  Cent  by 
Volume. 

Ratio. 

O.  oxvsen 

23.134 

20.92 

1.00 

76.866 

79.08 

3.78 

Having  the  composition  by  volume  of  a  gas,  its  calorific  power 
will  equal  the  sum  of  the  calorific  powers  of  its  constituents  calcu- 
lated as  shown  in  the  following  example : 


Constituents. 


Proportion 
by  Volume. 


CO 0.280 

CO2 0.038 

C2H4,  etc.,  illuminants 0 . 146 

H 0.356 

CH4 0.167 

1.087 


B.t.u.  per 
Cu.  Ft. 

X       349.5 

X  2000.0 
X  348.0 
X  1065.0 


Total  B  .t.u. 
in  Gas. 

97.86 

292.00 
123.88 

177.85 


Total      =     691.59 


292  AMERICAN  GAS-ENGINEERING  PRACTICE. 

It  is  necessary  that  the  volume  per  cents  be  reduced  to  0  deg. 
C.  (32  deg.  F.)  and  760  mm.  barometer,  which  are  the  standard 
conditions  for  a  gas;  also  that  exactly  the  proper  proportion  of 
oxygen  be  used  and  the  gases  and  water-vapor  formed  be  reduced 
to  0  deg.  C.  and  760  mm.  pressure,  the  basis  upon  which  the  values 
in  the  table  of  calorific  values  of  gases  are  calculated.  Generally 
the  temperature  assumed  in  works  conditions  is  60  deg.  F.  and 
atmospheric  pressure,  combustion  taking  place  in  air  instead  of 
oxygen.  Therefore  the  heat  added  by  the  air  and  gas  and  the 
heat  escaping  in  the  products  of  combustion  must  be  considered 
in  connection  with  the  B.t.u.  in  one  cubic  foot  of  gas  consumed 
under  standard  conditions.  Thus  one  cubic  foot  of  hydrogen  at 
32  deg.  F.  burned,  and  all  the  heat  conserved  at  32  deg.  F.,  will 
generate  348  B.t.u. ;  on  the  contrary  if  the  hydrogen  at  60  deg.  F. 
burns  in  such  a  way  that  its  products  escape,  containing  their  heat 
unutilized,  at  328  deg.  F,,  then  the  calorific  power  will  be  only 
264  B.t.u.;  in  the  same  limits  the  B.t.u.  of  CO  would  be  315  B.t.u., 
CH4  would  have  853  B.t.u.,  and  the  illuminants  would  have  1700 
B.t.u.  utilized  per  cu.  ft.  The  example  of  gas  previously  taken 
would,  under  these  limits  of  60  deg.  to  328  deg.  F.,  have  a  calorific 
power  of  only  552.83  B.t.u.  It  is  therefore  of  much  importance 
in  using  such  values  to  know  whether  they  are  reduced  to  standard 
conditions,  or,  if  not,  what  the  conditions  are  under  which  the 
result  given  was  calculated. 

THE    JUNKER   GAS-CALORIMETER. 

The  increasing  use  of  gas  for  fuel  purposes  is  making  the  heat- 
producing  value  of  relatively  greater  importance  than  the  candle 
power  as  determined  on  photometers.  Although  the  heat  value  of 
a  gas  can  be  estimated  by  calculation  from  an  analysis,  yet  the 
direct  determination,  in  an  apparatus  designed  to  burn  the  gas 
completely  and  collect  the  heat  in  such  a  manner  as  to  measure  it, 
is  more  rapid  and  direct.  Such  an  apparatus  is  called  a  calorim- 
eter, of  which  the  bomb  type  is  the  most  accurate,  but  the  Junker 
type  the  more  convenient  and  most  used.  Fig.  74  shows  the  ar- 
rangement of  this  apparatus,  complete.  The  gas  first  passes 
through  the  test-meter  provided  with  a  thermometer  for  tak- 
ing the  temperature  of  the  gas  before  combustion,  a  pressure- 
regulator,  Figs.  75  and  76,  to  insure  constant  pressure  at  the 
burner,  a  burner  removably  attached  and  adapted  to  regulate  the 
air  supply,  as  shown  by  the  detail  illustration,  Fig.  78,  a  calorim- 
eter vessel  hi  which  the  gas  is  burned  and  the  heat  absorbed  by 
circulating  water,  an  elevated  water  supply  flowing  under  constant 
head,  and  a  vessel  for  measuring  the  water  passing  through  it. 


PROPERTIES  OF  GASES. 


293 


The  details  of  the  calorimeter  body  are  illustrated  in  Fig.  77  (see  next 
page),  showing  how  the  consumed  gases  travel  up  the  combustion- 


FIG.  74. — General  Arrangement  of  Junker  Calorimeter. 


FIG.  75. — Section  of  Pressure-regulator,  C. 

chamber  and  pass  down  through  tubes  surrounded  by  water  and 
out  into  the  air  of  the  room  at  the  lower  opening.  The  heat  that 
enters  the  apparatus  is  contained  in  the  form  of  temperature  in  the 


294  AMERICAN  GAS-ENGINEERING  PRACTICE. 


FIG.  76. — Pressure-regulator  without  Liquid  Seal 


FIG.  77. — Junker  Gas-calorimeter  in  Section  and  Elevation. 


PROPERTIES  OF  GASES. 


295 


gas,  air,  and  water  entering  it,  and  in  combustible  constituents  in 
the  gas;  thermometers  are  therefore  necessary  to  test  the  tem- 
perature of  the  air  of  the  room,  of  the  gas  supplied,  and  of  the 
water  entering  the  apparatus.  The  heat  escaping  from  it  is  con- 
tained in  the  products  of  combustion  (water  of  condensation  and 
fuel-gas)  and  the  water  collected,  which  requires  two  more  ther- 
mometers. The  air-jacket  prevents  radiation  of  heat,  and  all 
essential  provisions  are  made  to  keep  heat  from  escaping  un- 
recorded. In  construction  the  apparatus  differs  slightly  accord- 
ing to  the  ideas  of  different  makers,  but 
the  principles  of  operation  remain  the 
same. 

The  apparatus  being  set  up  and 
properly  connected  by  rubber  tubes, 
water  is  run  into  the  elevated  tank 
and  through  the  apparatus  into  the 
drain  at  J  until  the  flow  is  steady, 
when  the  valve  can  be  set  with 
its  indicator  on  the  scale  so  that 
about  400  c.c.  of  water  will  flow  into 
the  graduate  D  per  minute;  there 
should  be  a  constant  but  slight  over- 
flow through  the  tube  6,  which  is 
regulated  by  a  valve  on  the  supply- 
tube  a.  The  water  level  in  the  wet- 
test meter  in  the  governor  and  U  tube 
H  are  of  course  looked  after  and  more 
water  added  if  necessary.  Remove  the 
Bunsen  burner  7,  Fig.  77,  to  prevent 
explosion,  turn  on  the  gas,  light  it, 
adjust  the  air-shutter,  and  replace, 
adjusting  the  gas-supply  to  keep  the 
difference  in  temperature  between  in- 
going and  outgoing  water  about  10  deg. 
C.,  during  which  time  about  3  liters  of 
water  are  passing.  The  rate  of  gas 
flow  will  be  governed  by  the  flame, 
which  should  be  of  proper  size  to  give 
out  about  1200  calories  per  hour.  Vari-  J 
ation  in  the  quality  of  gas  therefore 
will  require  more  consumption  for  the 
lean  gases  and  less  for  rich  gases,  the 
latter  requiring  also  a  considerable  air 
supply  and  the  lean  gases  very  little, 
if  any;  the  flue  damper  being  adjusted  accordingly. 


Junker's 


296  AMERICAN  GAS-ENGINEERING  PRACTICE. 

Having  the  apparatus  in  normal  operation,  a  test  is  begun  by 
taking  the  temperatures  of  the  air  in  the  room  near  the  calo- 
rimeter, the  temperatu  re  of  the  gas  going  through  the  meter  (G),  and 
the  temperature  of  the  gases  of  combustion  in  the  flue  at  J.  Then 
watch  the  meter-hand  until  it  is  at  a  convenient  starting-point, 
immediately  switch  the  outlet-tube  from  the  drain-funnel  to  the 
empty  graduate,  note  the  time,  temperature  of  water  entering  (F) 
and  leaving  (F')  as  quickly  as  possible  to  the  hundredth  part  of  a 
degree.  A  stop-watch  is  very  convenient  for  this  purpose,  one  that 
has  a  second  and  a  minute  hand,  and  reading-glasses  on  the  ther- 
mometers facilitate  that  part  of  the  work.  An  observation  is  com- 
pleted when  the  water  collected  reaches  a  little  over  1700  c.c.  in 
the  graduate,  when  the  readings  are  taken  as  at  the  start,  the  time 
being  noted  when  the  outlet-tube  is  removed  from  the  graduate  and 
the  meter  read.  The  temperature  of  inlet  and  outlet  water  is 
observed  about  every  half-minute. 

The  formula  for  calculating  the  calorific  value  of  a  gas  from 
these  observations,  given  in  metric  units,  is  as  follows  (see  Bates  on 
Calorimetry,  p.  25): 


„      . v^^-/r7TF)4-g(77/TF-77g)+^(77^-777TF) 

~G~ 

where  C= calories  per  cubic  meter; 

G= liters  of  gas  consumed  as  shown  by  the  meter; 
TOW=  temperature  of  outlet  water,  thermometer  F'', 
TIW= temperature  of  inlet  water,  thermometer  F] 

TG=  temperature  of  the  gas  at  meter,  thermometer  G; 
TEO= temperature  of  escaping  gases,  thermometer  J; 

W= water  collected  in  graduate  D  in  liters; 
K,  K'=  constants  calculated  from  the  specific  heats  of  the  aver- 
age quality  of  gases  by  Bates  as  follows,  in  calories: 

K  K' 

Natural  gas 0 .011  3.432 

Coal-gas 0.010  2.466 

Water-gas 0.009  1.353 

Producer-gas 0.0089  0.470 

In  case  the  heat  value  is  desired  under  standard  conditions,  say 
of  0  deg.  C.,  where  the  gas  is  more  dense  and  the  calorific  value 

27S  4-  Tr> 
naturally  higher,  the  value  of  C  is  multiplied  by  — === — .     There 


is  another  correction  not  yet  mentioned,  the  heat  carried  off  by  the 
moisture  condensed  from  the  water  vapor  formed  during  com- 


PROPERTIES  OF  GASES.  297 

bustion,  which  escapes  from  tube  No.  35  shown  in  the  section. 
When  1  kilogram  of  hydrogen  burns  to  form  9  kg.  of  water  vapor, 
at  100  deg.  C.  (212  deg.  Fah.)  it  generates  28732  calories,  but  if 
this  vapor  is  brought  to  0  deg.  C.  the  heat  given  up  is  34462,  the 
difference  being  due  to  the  latent  heat  of  the  steam  and  in  the 
water  formed.  As  calorimeter  results  may  vary  as  much  as  10 
per  cent  from  this  cause,  it  is  always  well  to  state  whether  the 
calories  found  are  gross  or  net.  The  correction  is  easy,  consisting 
in  deducting  from  the  calories  found  by  the  formula  0.636  calories 
per  cubic  centimeter  of  water  of  condensation  collected ;  as  less  than 
1  c.c.  of  water  is  thus  collected  per  liter  of  gas,  it  is  generally  meas- 
ured after  the  series  of  tests. 

Example.  In  a  5.5-minute  test  by  Bates  in  which  three  read- 
ings were  made  on  the  gases  and  twelve  on  the  water,  the  averages 
were  found  to  be:  7^=25.6  deg.,  7^=20  deg.,  TIW=  14.739  deg., 
T0w=  29.76  deg.,  (7=4.5  liters,  W  =1.74  liters.  Substituting  these 
values  in  the  formula  we  get 

„    1.740(29.76-14.739)  1000+0.01  (14.739-25.6) +2.466(20-14.739) 

4.5 

=5820.985  calories  per  cubic  meter. 

Applying  now  the  temperature  correction  we  find  that  at  0  deg.  C. 
the  calorific  value  will  be 

(273  +  2^  fi\ 
273      /     6344-8736  calories- 

To  reduce  this  to  B.t.u.  per  cu.  ft.  multiply  by  0.11236,  thus: 
6344.8736X0.11236=712.9099  B.t.u. 

Liquid  Fuels.— This  instrument  can  also  be  used  to  test  liquid 
fuels,  such  as  oils,  alcohol,  turpentine,  naphtha,  kerosene,  gasoline 
distillate  or  petroleum,  the  arrangement  of  apparatus  being  shown 
in  Fig.  79.  Instead  of  the  gas-meter,  governor,  and  burner  are 
substituted  scales  upon  one  arm  of  which  is  suspended  a  burner 
suitable  for  burning  the  liquid  fuel.  At  the  beginning  of  the  test 
the  lamp  is  lighted  and  inserted,  the  scales  are  balanced  with  the 
lamp  end  slightly  low,  the  water  supply  is  adjusted  as  with  gas, 
and  as  the  beam  comes  to  a  perfect  balance,  the  water-outlet 
is  switched  into  the  empty  graduate  and  readings  taken  as 
with  gas.  Place  a  weight  on  the  weight-pan  equal  to  the  quan- 


298  AMERICAN  GAS-ENGINEERING  PRACTICE. 


FIG.  79. — Junker's  Calorimeter  Adapted  for  Liquid  Fuels. 


PROPERTIES  OF  GASES. 


299 


tity  it  is  desired  to  test,  and  as  the  beam  again  comes  to  equilibrium 
take  final  readings  quickly.  The  calorific  value  is  then  calculated 
by  this  formula: 

W(Tow-TIW)lWOm 


where 


Gr 


C= calories  per  kilogram; 
GQ  =  weight  of  fuel  burned  in  milligrams; 


the  other  terms  being  the  same  as  before.  Calories  per  kilogram 
can  be  reduced  to  B.t.u.  per  pound  by  multiplying  the  calories 
by  1.8. 

THE  SIMMANCE-ABADY  GAS-CALORIMETER. 

With  the  purpose  in  mind  of  devising  a  calorimeter  by  which 
quick  tests  could  be  made  with  the  greatest  chance  of  accuracy, 


FIG.  80. — Arrangement  of  Simmance-     FIG.  81.— Sections  of  Simmance- 
Abady   Gas-calorimeter  with  Ther-  Abady  Calorimeter, 

mometers  Used. 


Messrs.  Simmance  and  Abady,  two  consulting  chemists  of  London, 
invented  the  calorimeter  which  bears  their  names.     It  is  of  the 


300  AMERICAN  GAS-ENGINEERING  PRACTICE. 

Junker  type  with  distinct  improvements.  Short  and  rapid  tests 
may  be  made  with  it,  taking  but  a  few  seconds  by  reason  of  the 
convenient  arrangement  of  instruments  to  be  read,  and  but  a 
minute  to  make  a  complete  test  for  calorific  power  of  a  gas.  The 
rapidity  at  which  gases  can  be  burned  can  be  regulated,  the  relative 
area  exposed  to  the  burning  gases  is  increased,  the  thermometers 
are  arranged  together  and  with  magnified  scales  for  quick  reading, 
the  head  of  water  entering  can  be  determined  with  positive  accu- 
racy, and  every  effort  made  to  secure  an  instrument  which  combines 
quickness  with  accuracy.  In  the  accompanying  illustrations 
the  water-inlet  is  shown  at  A,  cock  at  B,  whence  the  water  rises 
in  the  tube  C  to  a  height  equal  to  its  pressure,  flows  around  the 
thermometer  D  in  centigrade  degrees  divided  into  tenths,  thence 
through  annular  shells  E,  down  tubes  F,  up  through  tubes  G,  past 
the  baffle-plate  into  the  upper  space  H  containing  a  thermometer 
J,  and  escapes  at  K  either  through  the  waste-pipe  L,  or  into  the 
graduated  measure  M  of  1000  c.c.  capacity  in  2  c.c.  graduations. 
The  consumed  gas  rises  through  N  to  0,  where  the  temperature 
is  low  enough  for  the  water-vapor  formed  to  condense,  falls  down 
through  the  passages  P  to  the  chamber  below,  which  is  about  the 
temperature  of  the  air  entering  the  burner  chamber,  and  escapes 
through  a  shutter  with  thermometer  at  Q,  the  condensed  moisture 
being  collected  at  R.  For  every  cubic  centimeter  of  this  condensed 
vapor  of  water  thus  collected  per  cubic  foot  of  gas  burned  0.6 
calorie  must  be  deducted  from  the  gross .  calories  per  cubic  foot, 
or  2.382  B.t.u.  per  cubic  centimeter  per  cubic  foot  of  gas  burned 
must  be  deducted  from  the  gross  B.t.u.  per  cubic  foot.  In  setting 
up  the  calorimeter  the  instructions  of  the  makers  should  be  fol- 
lowed closely,  being  very  careful  in  handling  all  its  parts.  The 
gas  supply  must  be  under  uniform  pressure. 

The  operation  is  similar  to  that  of  the  Junker.  The  water 
supply  must  be  under  uniform  pressure,  preferably  from  an  elevated 
tank  provided  with  a  ball  valve,  as  indicated  by  the  height  of 
the  float  or  water  in  the  tube  C.  Light  the  gas-burner  outside 
ancj  put  it  in  place,  adjusting  the  flow  of  gas  to  get  the  best  com- 
bustion results,  adjust  the  damper  at  G  so  that  the  products  of 
combustion  are  of  the  same  temperature  as  the  entering  water, 
take  the  temperature  of  the  gas  and  air  of  the  laboratory,  and  the 
barometric  reading.  As  the  meter-hand  passes  zero  mark  turn 
the  outlet  running  water  into  the  graduate  M,  and  as  the  hand 
passes  a  determined  point,  say  12,  switch  the  water  back  into  the 
waste-drain ;  repeat  the  test  twice,  and  take  the  mean  of  the  three 
readings.  Suppose  362  c.c.  water  were  collected  in  M;  gas  burned 
12  divisions,  or  0.06  cu.  ft.;  difference  in  temperature  of  inlet  and 


PROPERTIES  OF  GASES.  301 

J5nd  E fetation  &*<**  £le*ali»n 


FiQ.  82.— The  Earnshaw  Blue-glass  Pyrometer. 


302  AMERICAN  GAS-ENGINEERING  PRACTICE. 

exit  water,  21.7  —  12.5=9.2  deg.  C.  The  makers  supply  a  table 
in  which  12  will  be  found  at  the  head  of  a  column,  362  in  left- 
hand  column,  and  18.1  opposite,  which  being  multiplied  by  9.2 
equals  166.52  calories  per  cu.  ft.;  or,  166.52X3.97  =  661.08  B.t.u. 
per  cu.  ft.  of  gas.  The  method  thus  simplified  is  not  laborious. 
Suppose  3  c.c.  of  condensation  water  was  collected,  or  36  c.c.  per 
cu.  ft.;  then  36X0.6  =  21.6  calories,  which  taken  from  166.52 
calories  leaves  144.92  calories  per  cu.  ft.,  net.  Or,  36X2.382 
=  85.75  B.t.u.,  which  subtracted  from  661.08  B.t.u.  is  575.32  B.t.u., 
net.  The  same  modifications  can  be  made  for  testing  oils  as 
described  under  the  Junker  instrument.  Another  improved  form 
has  been  devised  by  the  Metropolitan  Gas  Referees  of  London, 
which  aims  still  further  to  absorb  the  heat  of  combustion  by  the 
circulating  water. 

F.  TEMPERATURES. 

The  Earnshaw  Blue=glass  Pyrometer,  herewith  illustrated 
in  Fig.  82,  is  of  the  visual  type,  its  principle  being  the  absorption 
of  light  of  its  diminution,  through  the  use  of  a  varying  number  of 
slides  or  blue-glass  lenses  to  create  a  vanishing  point  of  light,  said 
light  of  course  presumed  to  vary  directly  as  the  intensity  of  the 
heat  observed. 

As  the  personal  equation  is  very  marked  in  the  use  of  an 
instrument  of  this  kind,  its  use  would  of  course  be  of  little 
service  in  establishing  absolute  values,  but  it  will  be  found  of 
extraordinary  usefulness  in  making  comparisons  or  establishing 
empiric  tests. 

Gas. — The  theoretical  flame  temperature  of  a  gas  is  the 
highest  temperature  that  can  be  obtained  by  the  combustion 
of  the  gas  when  no  heat  is  lost  in  any  way,  all  the  heat  that 
is  developed  being  employed  to  heat  up  the  products  of  com- 
bustion. 

Hydrogen  and  hydrocarbon  gases  containing  a  large  percentage 
of  hydrogen  yield  upon  combustion  large  weights  of  aqueous  vapor, 
which  has  a  high  specific  heat,  and  consequently,  in  spite  of  their 
high  heating  value,  do  not  produce  as  high  flame  temperatures  as 
do  such  gases  as  carbonic  oxide,  which  have  a  lower  heating  value, 
but  give  smaller  weights  of  products  having  a  lower  specific  heat 
than  aqueous  vapor. 

Since  when  the  gas  is  burned  in  air  the  weight  of  the  nitrogen 
mixed  with  the  oxygen  in  the  air  is  added  to  that  of 'the  products 
of  combustion,  the  flame  temperature  is  lower  when  the  combustion 
takes  place  in  air  than  it  is  for  combustion  in  oxygen,  as  is  practi- 
cally illustrated  in  the  oxyhydrogen  flame. 


PROPERTIES  OF  GASES.  303 

The  highest  temperature  that  can  theoretically  be  obtained  by 
burning  a  gas  in  air  is  the  temperature  that  will  be  reached  when 
no  heat  is  lost  in  any  way;  all  the  heat  developed  being  employed 
to  heat  up  the  products  of  combustion  and  the  nitrogen  accom- 
panying the  oxygen  drawn  from  the  air  for  this  combustion.  These 
conditions  are  of  course  never  obtained  hi  practice,  but,  as  it  is 
very  hard  to  measure  accurately  the  losses  that  occur  in  practice, 
the  maximum  theoretical  temperatures  are  used  to  furnish  a  basis 
for  comparisons  between  different  gases,  it  being  assumed  that  the 
'relations  between  the  temperatures  actually  obtained  will  be 
nearly  the  same  as  those  existing  between  the  theoretical  tempera- 
tures, although  the  absolute  temperatures  will  be  very  different  hi 
the  two  cases. 

This  maximum  theoretical  temperature  evidently  depends  upon 
the  quantity  of  heat  developed  by  the  combustion  of  a  unit  weight 
of  gas  and  upon  the  quantity  of  heat  required  to  raise,  by  one 
degree,  the  temperature,  of  the  products  resulting  from  the  com- 
bustion of  this  unit  weight,  and  the  quotient  obtained  by  dividing 
the  quantity  of  heat  produced  by  the  quantity  required  to  raise 
the  temperature  of  the  products  of  combustion  one  degree  will  give 
the  highest  temperature  that  can  be  reached  by  burning  the  given 
gas.  The  quantity  of  heat  produced  is  given  by  the  calorific  value 
of  the  gas.  The  amount  of  heat  required  to  raise  the  temperature 
of  the  products  of  combustion  one  degree  can  be  calculated  by 
multiplying  the  weight  of  each  product  that  is  produced  by  its 
specific  heat,  the  nitrogen  mixed  with  the  oxygen  in  the  air  and 
drawn  into  the  flame  with  it  being  included.  It  is  therefore  neces- 
sary to  determine  what  substances  are  produced  by  the  combustion 
of  the  gas  and  the  weight  of  each  of  these  substances  that  is  ob- 
tained from  the  unit  weight  of  the  gases,  to  multiply  the  deter- 
mined weight  of  each  substance  by  its  specific  heat,  and  to  add 
together  the  numbers  obtained  by  these  multiplications,  the  sum 
forming  the  divisor  of  the  fraction. 

The  maximum  temperature  that  can  be  produced  by  burning  a 
gas  in  air  can  therefore  be  determined  by  dividing  the  calorific 
value  of  the  gas  per  pound  by  the  sum  of  the  numbers  obtained, 
by  multiplying  the  weight  of  each  of  the  products  of  combustion 
produced  from  one  pound  of  gas  by  its  proper  specific  heat,  the 
nitrogen  mixed  in  the  air  with  the  oxygen  required  for  combustion 
being  considered  as  one  of  the  products  of  the  combustion. 

To  illustrate  by  a  simple  example,  the  maximum  temperature 
that  can  be  produced  by  the  combustion  of  carbonic  oxide,  CO, 
may  be  determined  as  follows: 

1  Ib.  of  CO  requires  for  its  combustion  to  carbonic  acid,  CO2, 
0.571  Ib.  of  oxygen,  which  will  have  mixed  with  it  in  the  air 


304 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


0.571X3.31  =  1.89  Ibs.  of  nitrogen,  N,  and  the  products  of  the 
combustion  of  1  Ib.  of  CO  will  therefore  be  1.571  Ibs.  of  CO2  and 
1.89  Ibs.  of  N.  The  calorific  value  of  CO  is  4383  B.t.u.  per  pound, 
the  specific  heats  of  CO2  and  N  are  respectively  0.217  and  0.244, 
and  the  equation  of  the  maximum  temperature  in  degrees  Fahren- 
heit is 


4383 


_4383 

1.571X0.217  +  1.89X0.244     0.802 


5465°  F. 


Melting=points. — For  the  determination  of  moderately  high 
temperatures,  such  as  that  of  hot  blast  supplied  to  furnaces,  use  is 
often  made  of  metals  or  alloys  of  known  melting-points,  and  wher- 
two  such  substances  are  procurable  with  melting-points  differing 
only  by  a  few  degrees,  the  temperature  of  the  blast,  etc.,  can  be 
readily  kept  within  that  range  by  regulating  the  heating  apparatus, 
so  that  one  test-piece  is  liquid  and  the  other  solid.  By  employing 
a  series  of  test-pieces  whose  melting-points  ascend  by  small  and 
fairly  regular  increments  a  tolerably  reliable  measurement  can  be 
made  of  any  temperature  within  the  range  of  the  test-pieces. 
Princeps  alloys  furnish  us  with  fairly  good  means  of  reading 
temperatures  between  the  melting-point  of  silver  and  that  of 
platinum. 


MELTING-POINTS   OF   PRINCEPS   ALLOYS. 


Percentage  Composition  of 
Alloy. 

Melting- 

Percentage  Composition  of 
Alloy. 

Melting- 

point, 
deg.  C. 

point, 
deg.  C. 

Silver. 

Gold. 

Platinum. 

Silver. 

Gold. 

Platinum. 

100 

954 

60 

40 

1320 

80 

20 

975 

55 

45 

1350 

60 

40 

995 

50 

50 

1385 

40 

60 

1020 

45 

55 

1420 

20 

80 

1045 

40 

60 

1460 

100 

1075 

35 

65 

1495 

95 

'S 

1100 

30 

70 

1535 

90 

10 

1130 

25 

75 

1570 

85 

15 

1160 

20 

80 

1610 

80 

20 

1190 

15 

85 

1650 

75 

25 

1220 

10 

90 

1690 

70 

30 

1255 

5 

95 

1730 

65 

35 

1285 

100 

1775 

The  values  of  the  higher  melting-points  are  probably  within  some  twenty 
degrees  of  the  truth. 


PROPERTIES  OF  GASES. 


305 


TEMPERATURES  OF  MOLTEN  IRON  CORRESPONDING  TO  CERTAIN 
COLORS  (POUILLET). 

Deg.  Fah. 

Intense  white 2730 

Bright  white 2550 

White  heat 2370 

Bright  orange 2190 

Orange 2010 

Bright  cherry 1830 

Cherry-red 1650 

Brilliant  red 1470 

Dull  red 1290 

Faint  red  .  977 


MELTING-POINT   OF   CAST   IRON. 

Deg.  Fah. 

White 1920  to  2010 

Gray 2010  to  2090 

Optical  Pyrometer. — The  St.  Jacques  Lunette  Pyrometrique 
is  a  polariscope  arranged  for  plane  polarized  light,  having  between 
the  analyzing  and  polarizing  prisms  a  quartz  crystal  about  11  mm. 
long  which  has  been  cut  perpendicular  to  its  principal  axis.  The 
plane  of  polarization  will  be  turned  by  such  a  piece  of  quartz 
through  an  angle  that  varies  directly  as  the  thickness  of  the  quartz, 
and  (approximately)  inversely  as  the  wave  length  of  the  light,  so 
that  the  amount  of  rotation  is  much  larger  for  the  violet  end  of 
the  spectrum  than  for  the  red.  The  higher  the  temperature  the 

INDICATIONS   OF  THE   LUNETTE   PYROMETRIQUE. 


Character  of  Light. 

Rotation 
Angle 
(Degrees). 

Approximate  Corresponding 
Temperature. 

C. 

Fah. 

Incipient  cherry-red  

33 
40 
46 
52 
57 
62 
66 
69 
84 

800° 
900 
1000 
1100 
1200 
1300 
1400 
1500 

1470° 
1650 
1830 
2010 
2190 
2370 
2550 
2730 

Cherry-red.  .       

Light  cherry-red 

Slightly  orange 

Bright  orange  ...                      .... 

White  .           .            

Welding  white  

Brilliant  white 

Bright  sunlight.  . 

306  AMERICAN  GAS-ENGINEERING  PRACTICE. 

larger,  the  proportion  of  light  rays  of  short  wave-lengths,  conse- 
quently the  larger  the  angle  through  which  the  analyzer  must  be 
rotated  in  order  to  obtain  the  " Extinction  Tint";  this  for  low 
temperatures  is  a  grayish  yellow  charged  by  a  slight  turning  of  the 
analyzer  in  either  direction  to  green  or  red ;  for  higher  temperatures 
it  is  the  same  as  for  sunlight,  a  neutral  purple  changing  to  blue  or 
red.  For  low  temperatures  where  the  light  is  feeble  a  condensing 
lens  is  employed  to  concentrate  the  beam  for  the  polarizer.  No 
useful  indication  can  be  obtained  below  incipient  cherry-red.  (See 
table  at  bottom  of  page  305.) 


TEMPERATURES. 

Degrees  Fahrenheit  =  £  Degrees  Centigrade +32,  or  F.°=1.8 
C.°+32. 

Degrees  Centigrade  =  |  (Degrees  Fahrenheit -32). 
Degrees  Absolute  Temperature,  T.  =  C.°+273. 
"  "  "  T.  =  F.°  +  491. 

Absolute  Zero=  —273°  on  Centigrade  Scale. 
"          «    =- 491°  on  Fahrenheit  Scale. 

Mercury  remains  liquid  to  —39°  C.,  and  thermometers  with  com- 
pressed N.  above  the  column  of  mercury  may  be  used  for  as  high 
temperatures  as  400°  to  500°  C.  . 

HEAT-UNITS. 

A  French  Calorie  =1  Kilogram  of  H2O  heated  1°  C.  at  or  near 
4°C. 

A  British  Thermal  Unit  (B.t.u.)  =  l  lb.  of  H2O  heated  1°  F.  at 
or  near  39°  F. 

A  Pound-Calorie  Unit  =  1  lb.  of  H2O  heated  1°  C.  at  or  near  4°  C. 

1  French  Calorie  =  3.968  B.t.u.  =  2.2046  Pound-Calories. 

1  British  Thermal  Unit  =  .252  French  Calories  =.555  Pound- 
Calories. 

1  Pound-Calorie  =1.8  B.t.u.  =  .45  French  Calories. 

1  B.t.u.  =  778  ft .-lbs.  =  Joule's  mechanical  equivalent  of  heat. 

1  H.P.   =33,000  ft.-lbs.  per  minute 

=  8^004  =  42.42  B.t.u.  per  minute 
=  42.42X60  =  2545  B.t.u.  per  hour. 

The  British  Board  of  Trade  unit  is  not  a  unit  of  heat,  but  of 
electrical  measurement  and 

=  1  kilowatt  hour 

=  1000  watts  =  SW=  1.34  H.P.  per  hour. 


PROPERTIES  OF  GASES. 


307 


TEMPERATURES   IN   SOME    INDUSTRIAL   OPERATIONS. 

Centigrade  Fahrenheit 

Degrees.  Degrees. 

Gold — Standard  alloy,  pouring  into  molds 1180  2156 

Annealing  blanks  for  coinage,  furnace  cham- 
ber      890  1634 

Silver — Standard  alloy,  pouring  into  molds 980  1796 

Steel — Bessemer  Process,  Six-ton  Converter: 

Bath  of  Slag 1580  2876 

Metal  in  ladle 1640  2984 

"     "  ingot  mold 1580  2876 

Ingot  in  reheating  furnace 1200  2192 

"     under  hammer 1080  1976 

Siemens  Open-hearth  Furnace: 

Producer-gas  near  gas-generator 720  1328 

' '       entering  recuperator  chamber  . . .     400  752 

leaving            "               "         ...   1200  2192 

Air  issuing  from                                               ...   1000  1832 

Products  of  combustion  approaching  chimney.     300  590 

End  of  melting  pig  charge 1420  2588 

Completion  of  conversion 1500  2732 

Pouring  steel  into  Iad.e  {  Jg^; ; ; ; ;      ; ; ;  «*j  gJJ 

In  the  molds 1520  2768 

Siemens  Crucible  Furnace: 

Temperature  of  hearth  between  crucibles 1600  2912 

Blast-furnace  on  Gray  Bessemer: 

Opening  in  front  of  tuyere 1930  3506 

, ,  , .            ,   i                  j  beginning  to  tap 1400  2552 

Moltenmetal 1  end  of  tap  .  •  •  • 1570  2858 

Siemens  Glass-melting  Furnace: 

Temperature  of  furnace 1400  2552 

Melted  glass 1310  2390 

Annealing  bottles 585  1085 

Furnace  for  hard  porcelain,  end  of  "baking"..    1370  2498 

Hoffman  red-brick  kiln,  burning  temperature..   1100  2012 

MELTING-POINTS. 
P. 

Sulphur 115            239        Copper 1054  1929 

Tin 230            446      |  Cast  iron,  white. .  .       1135  2075 

Lead 326            618          "      "      gray...       1220  2228 

Zinc 415            779        Steel,  hard 1410  2570 

Aluminium 625          1157          "      mild 1475  2687 

Silver 945          1733      |  Palladium 1500  2732 

Gold 1045          1913      i  Platinum 1775  3227 


308 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


MELTING-POINTS  (ANOTHER  AUTHORITY). 


Substance. 

Degrees  Fah. 

Substance. 

Degrees  Fah. 

Aluminium 

1247 

Phosphorus 

Ill 

Antimony 

797 

Platinum 

3227 

Bismuth                  .  .  . 

505 

Potassium 

136 

Bronze  

1652 

Silver  

1832 

Butter 

91 

Sodium 

203  to  204 

Copper 

2102 

Spermaceti. 

120 

Gold 

2192 

Stearine.  .  . 

131 

"     coined  

2156 

Steel  

2372  to  2552 

Ice                  

32 

Sulphur  ,  

230 

Iodine  

237 

Tin  

540 

Iron  cast 

1922  to  2382 

Wax,  white 

154 

'  '      wrought  . 

2732  to  2912 

Wax,  yellow 

144 

Lead                  

617 

Zinc  

786 

G.     HEAT  DATA. 

Heat  Radiation. — Good  heat  radiators  are  good  absorbers  to 
an  equal  degree,  and  reflecting  power  is  the  exact  inverse  of  radiat- 
ing power. 

EELATIVE    VALUE    OF  RADIATORS. 
Substance.  Relative^Radiating 

Lampblack  or  soot 100 

Cast  iron,  polished 26 

Wrought  iron,  polished 23 

Steel,  polished 18 

Brass,  polished 7 

Copper,  polished 5 

Silver,  polished 3 

Conduction  is  the  transfer  of  heat  by  contact,  molecular  motion 
being  then  directly  caused.  Heat  is  thus  transmitted  through 
the  thickness  of  a  furnace-tube.  There  are  good  and  bad  con- 
ductors, the  former  being  chosen  for  fire-boxes,  other  properties 
being  suitable. 

RELATIVE   VALUE    OF   GOOD   HEAT   CONDUCTORS. 
Substance.  Relative^Conducting 

Silver 100* 

Copper 73.6 

Brass 23.1 

Iron 1.91 

Steel 11.6 

Platinum 8.4 

Bismuth 1.8 

Water..  0.147 


PROPERTIES   OF  GASES.  309 

Bad  conductors  are  of  value  for  covering  boilers,  steam-cylin- 
ders, pipes,  etc. 

RELATIVE    VALUE    OF   HEAT   INSULATORS. 
Substance.  Relative^Insulating 

Silicate  cotton  or  slag  wool 100 

Hair  felt 85.4 

Cotton  wool 82 

Sheep's  wool 73.5 

Infusorial  earth 73 . 5 

Charcoal 71 . 4 

Sawdust 61 .3 

Gas-works  breeze 43 . 4 

Wood,  and  air-space 35 .7 

EXPANSION    OF   LIQUIDS   IN   VOLUME. 
Volume  at  32  deg.  Fah.  =  l.  Volume  at  212  deg.  Fah. 

Water 1.046 

Oil 1.080 

Mercury 1 .018 

Spirits  of  wine 1 . 110 

Air 1.373  to  1.375 

LINEAL   EXPANSION    OF   METALS    PRODUCED    BY   RAISING   THEIR 
TEMPERATURE    FROM   32°   TO   212°    FAH. 


Zinc 1  part  in  322 

Lead "  "  "  351 

Tin  (pure) "  "  "  403 

Tin  (impure) "  "  "  500 

Silver "  "  "  524 

Copper "  ll  "581 

Brass..                   .  "  "  "  584 


Gold 1  part  in    682 

Bismuth "  "  "     719 

Iron "  "  "     812 

Antimony "  "  "     923 

Palladium "  "  "  1000 

Platinum "  "  "  1100 

Flint  glass "  "  "  1248 


COEFFICIENTS    OF   LINEAR    EXPANSION. 

Elongation  per 
deg.  C. 

Glass 0.0000085 

Platinum 0000085 

Cast  iron 00001 

Wrought  iron 000012 

Copper 000017 

Lead 000028 

Zinc 00003 

Brass.  .  .000019 


310 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


RELATIVE  POWER  OF  METALS  FOR  CONDUCTING  HEAT. 

Iron 374.3 

Zinc 363 

Tin 303.9 

Lead. .  .179.6 


Gold 1000 

Silver 973 

Copper 898.2 

Platinum.  .  381 


Quantity  of  Heat  Lost  by  a  Square  Unit  of 
Exterior  Pipe  Surface 


Excess  of  Temperature  in  the  Gas  in  the  Pipes 
over  that  of  the  Atmosphere. 
For  an  Excess  of 

When  Radiating 
in  Air. 

When  Plunged 
in  Water. 

10°.  . 

8 
18 
29 
40 
53 

88 
266 

5,353 
8,944 
13,437 

20°.  . 

30° 

40° 

50° 

COMPARATIVE    POWER    OF   SUBSTANCES    FOR   REFLECTING  RADIANT 

HEAT. 

Polished  brass 100 

Silver 90 

Tin 80 

Steel 60 

Lead 60 

Glass 10 

Lampblack 0 


RELATIVE    POWER    OF   METALS   FOR   REFLECTING   HEAT. 
Intensity  of  direct  radiation  =1.00. 


Silver  plate 0.97 

Gold 0.95 

Brass 0.93 

Speculum  metal 0 . 86 

Tin..  .  0.85 


Polished  platinum 0.80 

Steel 0.83 

Zinc 0.81 

Iron. .  .0.77 


CHAPTER  XX. 


STEAM. 

A.     PROPERTIES  OF  STEAM. 

THE  conversion  of  water  into  steam  is  attended  with  certain 
heat  phenomena  which  may  be  developed  as  follows: 

Latent  Heat.— The  term  latent  heat  is  applied  to  the  heat 
added  to  or  abstracted  from  a  substance  to  change  its  state  with- 
out changing  its  temperature.  Thus  144  B.t.u.  must  be  added 
to  1  pound  of  ice  to  convert  it  into  water  at  32  deg.  F.  This  can 
be  found  by  direct  experiment  by  allowing  ice  to  melt  in  water, 
the  heat  lost  by  the  water  being  absorbed  by  the  ice.  Suppose 
2  oz.  (wi)  of  ice  at  32  deg.  F.  are  added  to  20  oz.  of  water  (w)  at 
60  "deg.  F.  (ti)  which  was  at  45  deg.  F.  when  the  ice  was  melted, 
1  deg.  being  obtained  from  the  higher  temperature  of  the  room, 
making  the  corrected  final  temperature  (t2)  44  deg.  F.  Then 

Heat  lost  by  the  water  =  heat  gained  by  the  ice. 
wfo-ti)  =w][L+(t2-32)]} 

20  (60  -  44)         =  2[L  +  (44  -  32)], 
Latent  heat,  L=  (320-24)^2=148. 

The  exact  value  is  more  nearly  144 
B.t.u.  The  calorimeter  shown  in  Fig.  83  is 
often  used  for  such  experiments.  A  metal 
vessel  B  contains  in  its  air-space  another 
vessel  surrounded  by  non-conducting  ma- 
terial like  felt  and  is  provided  with  a  ther- 
mometer for  taking  the  temperature  of 
the  water.  The  Siemens  pyrometer  resem- 
bles this  apparatus,  the  copper  cylinder 
being  brought  up  to  the  temperature  of  the 
furnace  to  be  tested  and  then  quickly 
thrown  into  the  known  weight  of  water; 
when  the  temperature  becomes  constant 
after  gently  stirring  the  heat  lost  by  the 
copper  will  equal  the  heat  gained  by  the 

water,  as  before,  but  the  calculation  is  as    -^ 

FIG.  83. — Calorimeter, 
follows : 

311 


312 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


Weight  >  specific  heat  X  decreased  temperature  of  copper 

=  weight  X  increased  temperature  of  the  water. 


where  T  is  the  temperature  of  the  furnace  and   the  other  terms 
have  the  same  values  as  before. 

When  water  is  heated  the  rise  in  temperature  ceases  at  212  deg. 
F.  (100  deg.  C.)  until  all  the  water  has  been  converted  into  steam 
without  raising  the  pressure.  The  heat  continually  added  goes 
to  change  the  condition  of  water  from  that  of  a  liquid  to  a  vapor. 
This  heat  may  be  determined  by  the  apparatus  shown  in  Fig.  84. 


FIG.  84.  —  Apparatus  for  Testing  Latent  Heat  of  Steam. 

Water  is  boiled  in  flask  A,  steam  passing  from  A  through  B  to  flask 
C  into  water,  which  condenses  it.  This  continues  until  the  water 
in  C  nearly  boils.  The  difference  in  weight  of  C  before  and  after 
the  test  will  give  the  weight  of  steam  condensed  (w).  Since  the 
heat  lost  by  the  steam  equals  that  gamed  by  the  water, 


or  if  there  was  20  oz.  of  water  in  C  at  70  deg.  F.  and  the  steam 
condensed  was  1.5  oz.,  increasing  the  temperature  to  147  deg., 

1.5(212  +  1*-  147)  =  20(147-70), 
Lh=  (1540-97  5)+-  15  =  931.6  B.t.u. 

The  exact  value  for  the  latent  heat  of  steam  is  966  B.t.u. 

It  should  be  well  grasped  that  latent  heat  is  a  kind  of  specific 
heat  given  to  the  body  during  the  change  from  solid  to  liquid  and 
from  liquid  to  gaseous.  In  the  reverse  order  an  equal  quantity  of 
heat  is  given  out.  Thus  1  Ib.  of  ice  below  32°  will  give  out  or 
absorb  0.5  unit  for  every  degree,  and  144  units  when  melting. 
Water  between  32°  and  212°  will  require  1  unit  per  Ib.  Finally,  if 
the  steam  be  superheated  beyond  212°,  0.48  unit  will  raise  each 
pound  by  one  degree  at  a  time. 


STEAM. 


313 


Fig.  85  shows  the  changes  indicated,  ABC  being  the  curve  of 
volumes,  with  DEF  as  base,  and  the  dotted  line  a  curve  of  corre- 


NCREASINQ  WITH  TEMP.  BYxGAY  LUSSAC'S  FORMULA 


spending  temperatures.    The  base-line  lengths  indicate  units  of 
heat  required  to  change  both  volume  and  temperature  under  atmos- 


314 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


pheric  pressure.  The  steam  volume  at  F  is  too  great  to  be  shown 
on  the  diagram,  but  is  given  to  a  smaller  scale  at  G  and  to  a  still 
smaller  scale  at  C.  The  base  of  these  narrow  triangles  corresponds 
to  EF. 

Water  will  boil  at  212°  F.  under  14.7  Ibs.  per  sq.  in.  pressure, 
but  if  the  pressure  is  decreased  the  boiling-point  is  lowered,  and  if 
the  pressure  increases  the  boiling-point  will  be  above  212  deg. 
When  steam  is  in  contact  with  boiling  water  it  is  wet  or  saturated, 
but  when  all  water  has  been  evaporated  it  becomes  dry  steam; 
further  addition  of  heat  forms  superheated  steam,  which  behaves 
like  a  fixed  gas  in  that  condition.  In  Fig.  85  the  volume  of  steam 
is  1650  times  that  of  the  water  from  which  it  was  formed,  while 
1  Ib.  of  water  will  form  26.36  cu.  ft.  of  steam. 

The  relation  of  temperature  to  pressure  for  the  range  of  —32 
to  32  deg.  F.  was  tested  by  Gay-Lussac  hi  the  apparatus  shown  in 


FIG.  86.  FIG.  87. 

FIG.  86. — Tension  of  Aqueous  Vapor  at  Low  Temperatures. 
FIG.  87. — Tension  of  Aqueous  Vapor  at  Medium  Range. 

Fig.  86,  consisting  of  two  barometer  tubes  hi  mercury,  tube  B 
containing  some  water  above  the  mercury  in  its  end,  the  tempera- 
ture of  which  was  regulated  by  freezing-mixtures  as  shown. 

For  the  temperature  ranges  from  32  deg.  to  122  deg.  Itegnault 
used  the  apparatus  shown  in  Fig.  87,  hi  which  tube  B  again  has  a 
little  water  on  the  surface  of  the  mercury.  The  ends  of  the  barom- 
eter tubes  are  surrounded  by  water  which  is  readily  brought  to 
the  temperature  desired. 

The  tension  of  aqueous  vapor  and  steam  between  the  tempera* 
tures  of  122  deg.  and  219  deg.  F.  (since  it  has  been  carried  to  432 


STEAM. 


315 


deg.)  was  found  by  Regnault  in  the  apparatus  shown  in  Fig.  88, 
where  A  is  a  boiler  in  which  steam  is  formed  which  is  condensed 
by  the  water-jacket  circulating  water  from  D  to  E,  B  is  a  copper 
sphere  in  which  the  pressure  is  regulated  by  the  pump  C  and 
measured  by  the  U  gage  F.  The  thermometers  in  A  measure  the 
temperature  of  the  steam,  and  the  very  high  tube  G  permitted  of 
pressures  up  to  24  atmospheres. 

The  relation  between  temperature  and  specific  volume  or  cubic 
feet  per  pound  was  determined  by  Fairbairn  and  Tate  in  the  appa- 
ratus shown  in  Fig.  89,  where  a  glass  sphere  A  dips  its  open  stem 
into  mercury  in  tube  E  connected  with  B,  containirg  water.  A 
known  weight  of  water  is  placed  in  A  while  D  and  B  are  heated. 
As  the  tension  in  A  and  B  are  eqr.al  at  first  the  mercury  columns 
are  at  the  same  level,  but  when  the  water  in  A  has  evaporated, 


FIG.  88.— Vapor  Tension 
of  Steam. 


FIG.  89.— Testing  for 
Specific  Volume. 


the  vapor  begins  to  superheat  and  the  pressure  becomes  less  than 
in  B,  which  is  still  evaporating,  so  that  the  mercury-column  levels 
separate.  At  this  moment  the  steam  in  A  is  dry,  its  volume  is 
known,  and  its  weight,  from  which  its  specific  volume  at  that  tem- 
perature is  readily  found.  The  results  from  these  experiments  are 
shown  by  the  curves  of  Fig.  90,  where  the  curve  to  the  left  shows 
the  rise  in  temperature  and  the  curve  to  the  right  the  decrease  in 
specific  volume  as  the  absolute  pressure  (at mospheric-f  pressure 
above  atmospheric)  increases. 

The  total  heat  of  evaporation  is  the  quantity  of  heat  required 
to  raise  the  temperature  of  water  from  freezing-point  to  boiling- 
point  and  just  convert  it  into  steam.  Regnault  investigated  the 


316 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


total  heat  of  steam  in  an  apparatus  shown  in  Fig.  91,  consisting  in 
a  steam-boiler  from  which  steam  was  taken  through  c  into  a  coil, 
A,  immsrsed  in  water  connected  with  a  bulb,  B,  in  which  the  pres- 
sure could  be  regulated  by  the  pump  shown,  and  measured  by  the 
mercury  column  as  shown  in  Fig.  88.  Thermometers  showed  the 
temperatures  of  steam  and  cooling-water.  From  his  experiments 
Regnault  found  that  the  total  heat  was  equal  to  1092+0.3  (£°-32°). 
By  deducting  the  sensible  heat,  t°— 32°,  the  latent  heat  remained 


•  800  200 

TEMPERATURE     FAH. 


VOL.  1  LB     WT. 


FIG.  90. — Relation  of  Pressure,  Temperature,  and  Volume  of  Saturated 

Steam. 


as  1092-0.7  (/°-32°).  To  find  a  formula  applicable  to  any  tem- 
perat-ure  for  saturated  steam  above  or  below  212  deg.  this  formula 
becomes 

L=966-0.7(Z°-212°)  =  1115-0.7$°. 


STEAM. 


317 


In  condensing  steam  the  heat  lost  by  the  steam  equals  the  heat 
gained  by  the  water.     Suppose  the  temperature  of  exhaust-steam 


o — « 


FIG.  91. — Testing  for  Total  Heat  in  Steam. 


FIG.  92.— Graphical  Diagram  showing  Distribution  of  "Work. 

to  be  193  deg.  F.,  that  of  the  condensing  water  on  entering  60  deg. 
and  at  exit  120  de«'.,  then 

966-0.7(212- 193)  +  (193- 120)  =  ^(120-60), 
W=17.53  Ibs. 


318  AMERICAN   GAS-ENGINEERING  PRACTICE. 

Work  in  Steam. — When  steam  is  formed  it  occupies  a  relatively 
much  greater  volume  than  the  water  from  which  it  had  been 
formed;  this  expansion  could  take  place  only  against  the  resistance 
of  material  previously  occupying  that  space,  and  work  is  therefore 
done.  This  is  illustrated  in  Fig.  92.  where  one  pound  of  water  is 
supposed  to  be  heated  in  the  tube  having  a  piston  above  it  of  1 
square  foot  area.  The  steam  pushes  it  upward  against  one  atmos- 
phere, or  14.7  Ibs.  per  sq.  in.,  or  14.7X144  =  2116.8  Ibs.  As 
1  cu.  ft.  of  water  weighs  62.5  Ibs.  it  will  stand  1-^-62.5  =  0.016  foot 
high  in  the  tube.  The  specific  volume  of  1  Ib.  of  steam  at  212 
deg.  is  26.36  cu.  ft.,  attained  by  doing  2116.8X26.36  =  55,799  ft.- 
Ibs.  of  work.  The  latent  heat  of  steam  absorbed  966  X  772  =  745,752 
ft.-lbs.  Taking  from  this  55,799  leaves  689,935  ft.-lbs.  for  internal 
work.  Raising  the  temperature  of  water  from  60  deg.  to  212  deg. 
required  152X772=117,344  ft.-lbs.  This  may  be  summed  up  as 

Total  work  =  [966 +  180°- (60° -32°)]772= 863,096  ft.-lbs. 

Thus  2. 1  parts  of  the  work  went  to  raise  the  temperature  of  the 
water  12.36  to  internal  work  of  changing  water  into  steam  and  1 
part  to  external  work  of  raising  the  piston  or  expansion.  In  the 
diagram  let  OA  be  26.36  and  OB  2116.8  Ibs.;  then  the  shaded 
rectangle  will  represent  external  work.  Make  OD  and  DE  12.36 
and  2.1  times  OB  respectively;  the  rectangle  OD  arid  DG  will  rep- 
resent internal  work  and  sensible  heat  respectively.  The  shaded 
area  represents  only  useful  work.  The  efficiency  of  steam-for- 
mation work  therefore  is  55,799^863,096  =  0.0646.  Using  these 
figures,  let  us  take  the  example  of  a  triple-expansion  engine  operat- 
ing with  steam  at  160  Ibs.  gage  pressure,  or  160  +  14.7=174.7  Ibs. 
absolute  pressure.  Thence  we  have 

Specific  volume  of  steam,  cu.  ft 2.5 

Load  on  piston,  144X  174.7  Ibs 25,156.0 

External  work,  2.5X25,156  Ibs 62,890.0 

Temperature  of  steam,  deg.  F 370.0 

Latent  heat,  [966 -0.7 (370- 212)] X 772  ft.-lbs 660,369.0 

Internal  work,  660,369-62,890  ft, -Ibs 597,479.0 

Raising  temperature  of  water,  (370-60)772  ft.-lbs 239,320.0 

Total  work,  62,890  +  597,479  +  239,320  ft.-lbs 899,689.0 

-^~  .  -   ,  external  work       62,890 

Efficiency  of  steam  =    .    .   . -, — =  nn  1on=Q-Q7, 

total  work        899,189 

which  shows  that  high-pressure  steam  is  not  more  economical  than 
low-pressure  steam,  weight  for  weight. 

Specific  Heat. — The  relative  quantity  of  heat  required  to  raise 
the  temperature  of  a  substance  1  deg.  F.,  as  compared  with  water, 


STEAM  319 

is  termed  its  specific  heat.  As  applied  to  gases  it  refers  to  two  con- 
ditions —  constant  volume  and  constant  pressure,  the  temperature 
varying  in  both  cases.  As  1  cu.  ft.  of  air  weighs  0.0803  lb.,  1  Ib. 
will  occupy  12.4  cu.  ft.  at  1  atmosphere  pressure  and  32  deg.  F. 
If  it  is  heated  to  212  deg.  F.,  a  rise  of  180  deg.  F.,  the  increase  in 
volume  will  be  (180-^-492)12.4  =  4.54  cu.  ft.,  which  represents  the 
rise  of  the  piston  in  Fig.  92  against  2116.8  Ibs.  '  The  external  work 
will  therefore  be  2116.8X12.4  =  9510.27  ft.-lbs.  The  specific  heat 
of  gases  at  constant  pressure  is  0.2375;  thus  the  heat  absorbed  in 
raising  the  temperature  of  the  air  180  deg.  will  be  180X0.2375  = 
42.75  B.t.u.  =  33,003  ft.-lbs.  The  difference,  which  is  internal 
work,  will  therefore  be  33,003-9510.27  =  23,492.75  ft.-lbs.  = 
30.43  B.t.u.  Therefore  the  specific  heat,  constant  volume,  = 
30.43-^180  =  0.1672  B.t.u.,  or,  more  correctly,  0.1686  B.t.u. 
The  ratio  of  specific  heats  will  therefore  be  0.2375^0.1686= 
lAOS=y.  When  specific  heats  are  represented  in  foot-pounds  the 
symbols  Kp  and  K9  may  be  used. 

According  to  Regnault's  law  the  specific  heat  of  a  gas  at  con- 
stant pressure  is  the  same  at  all  temperatures.  Suppose  a  gas 
to  be  heated  under  the  constant  pressure  P,  its  volume  being 
increased  from  V\  to  V2  and  the  absolute  temperature  rising  from 
Tl  to  T2,  then  the 

External  work=P(72-F])  =  c(772-771); 

Total          "    =  KP(T2-T1), 

Internal      "    =Kp(T2-771-c(772-r1). 

Since  only  internal  work  is  done  when  gas  is  heated  at  constant 
volume, 


C=  Kp  —  Kv. 

Note  that  the  internal  work  Kv(T2  —  Ti)  may  be  either  positive, 
negative,  or  nothing. 

Superheated  Steam.  —  By  experiment  Kp=  370.56  ft.-lbs. 
Steam  behaves  like  a  perfect  gas  a  few  degrees  above  its  saturation 
point,  Kp  being  practically  a  regular  quantity.  The  ratio  of  the 
specific  volumes  of  air  to  superheated  steam  is  0.622,  and  the 
constant  C  for  steam  equals  the  constant  C  for  air  divided  by 
0.622  or  85.5.  Therefore 

0=^-^=85.5,        #„  =  370.56  -85.5  =285.06  ft.-lbs., 
Kp    370.56 


320 


AMP:RICAN  GAS-ENGINEERING  PRACTICE. 


Expansion  Curves. — The  hyperbola  illustrating   Boyle's   law 
is  shown  in  Fig.  93,  and  expresses  the  relation 

PV=C. 


FIG.  93.  —  Hyperbolic  Expansion  Curve.  FIG.  94.  —  Expansion  Area. 

Another  expansion  curve  has  the  formula  PVn=C,  the  exponent 
n  changing  with  the  material.  The  shaded  area  shows  the  work 
done  during  expansion,  Fig.  94,  and  could  be  measured,  but  since 
the  curve  has  a  definite  formula  its  area  may  be  found  by  the 
formula 


~. 

This  of  course  requires  the  use  of  a  table  of  hyperbolic  logarithms. 
The  area  of  the  curve  having  the  formula  PVn=C  is 


Area= 


rc-1 

An  isothermal  curve  follows  the  law  of  Boyle,  the  heat  trans- 
formed into  work  during  expansion  being  supplied  so  that  the 


FIG.  95. — Expansion  Curves.        FIG.  96. — Compression  Curves. 

temperature  remains  constant.     If  no  heat  is  supplied,  the  curve 
will  fall  below  the  hyperbola  as  shown  in  Fig.  95.     In  compression 


STEAM.  321 

the  curve  would  rise  above  the  isothermal  as  the  gas  becomes 
heated  by  work  done  upon  it,  as  shown  in  Fig.  96. 

The  value  of  the  exponent  n  for  the  adiabatic  expansion  curve 
is  thus  developed : 


Area  of  curve  =  PlVl     ^2  =  -^  (T2  -  Tfi  =  external  work. 

71       1  71  —  J. 


Total  work     =  internal  work  +  external  work 


Since  no  heat  is  added  nor  abstracted  in  adiabatic  expansion  this 
last  expression  is  equal  to  zero;  since  the  factor  (T2  —  TI)  is  tangible, 


nKv  —  Kp=0     and    n=-^=y, 
Ar 

and  PVy=C 

is  the  general  equation  for  adiabatic  expansion.  External  work 
is  done  at  the  expense  of  the  heat  in  the  gas.  Therefore,  in  adia- 
batic expansion 

P2V2y=  Pl  VS,        P2V2V2»-i  =  Pl  V,  TV-i, 

(FA^"1  /FA^"1 

vj    =cT*=cT\v2)    ' 

(rr  \y-l  /T.\  0.408 

il)      ,        or    Ti-T  for  air. 


322 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


The  formula  thus  far  developed  may  now  be  collected: 

Isothermal  expansion,  PV  =  C, 

.,.  ,    ,.  ,-.T7<     „  (  y=  1.408  for  air 

Adiabatic  PVy=C  [  y  =  1>3  forsup 

Saturated  steam  expansion,      PV^=C  (Rankine)  =  475, 
Adiabatic     "  "  p  71.235 = Q  (Zeuner) , 

PV¥=C  (Rarjkine), 
superheated  steam  expansion,  PF1-3  =  C. 

These  adiabatic  curves  represent  the  expansion  of  steam  in  a 
cylinder  under  good  conditions.     As  shown  in  Fig.  97,  all  start- 


FIG.  97. — Curves  Compared. 

ing  at  the  same  point,  the  hyperbolic  curve  lies  highest  and  the 
adiabatic  for  air  lowest. 

By  consulting  Fig.  98  it  will  be  seen  that  AB  is  the  curve  for 
dry  steam;  if  V  is  decreased  by  compression  at  constant  tempera- 


FIG.  98. — Curves  of  Wet  and  Dry  Steam. 

ture  the  steam  becomes  wet,  but  if  V  is  increased  the  steam  becomes 
superheated  and  has  the  formula  PVl-135=C.  Tables  I  and  II 
give  the  properties  of  dry  saturated  steam  and  facts  connected 
with  steam  generation. 

Table  II  gives  the  properties  of  dry  saturated  steam  for  differ- 
ences of  1  Ib.  per  sq.  in.  pressure  and  ranges  usual  in  steam- 
boiler  practice. 


STEAM. 


323 


I.  PROPERTIES   OF  SATURATED   STEAM. 


Abso- 
lute 
Pres- 
sure. 

Gage 
Pressure. 

Temper- 
ature F. 

Weight  in 
'ounds  per 
Cubic  Foot 
of  Steam. 

Volume  in 
Cubic  Feet 
of  One 
Pound  of 
Steam. 

Total  Heat  above 
32°  F. 

Latent 
Heat, 
Heat- 
units. 

In  the 
Water, 
Heat- 
units. 

In  the 
Steam, 
Heat- 
units. 

1 

-27.9 

102.1 

.003 

334.23 

70.09 

1113.1 

1043.0 

5 

-19.7 

162.3 

.014 

72.50 

130.7 

1131.4 

1000.7 

10 

-  9.6 

193.2 

.026 

37.80 

161.9 

1140.9 

979.0 

14.7 

0. 

212.0 

.038 

26.36 

180.9 

1146.6 

965.7 

15 

.3 

213.0 

.039 

25.87 

181.9 

1146.9 

965.0 

20 

5.3 

227.9 

.050 

19.72 

197.0 

1151.5 

954.4 

25 

10.3 

240.0 

.063 

15.99 

209.3 

1155.1 

945.8 

30 

15.3 

250.2 

.074 

13.48 

219.7 

1158.3 

938.9 

35 

20.3 

259.2 

.086 

11.66 

228.8 

1161.0 

932.2 

40 

25.3 

267.1 

.097 

10.28 

236.9 

1163.4 

926.5 

45 

30.3 

274.3 

.109 

9.21 

244.3 

1165.6 

921.3 

50 

35.3 

280.9 

.120 

8.34 

251.0 

1167.6 

916.6 

55 

40.3 

286.9 

.131 

7.63 

257.2 

1169.4 

912.3 

60 

45.3 

292.5 

.142 

7.03 

262.9 

1171.2 

908.2 

65 

50.3 

297.8 

.153 

6.53 

268.3 

1172.8 

904.5 

70 

55.3 

302.7 

.164 

6.09 

273.4 

1174.3 

900.9 

75 

60.3 

307.4 

.175 

5.71 

278.2 

1175.7 

897.5 

80 

65.3 

311.8 

.186 

5.37 

282.7 

1177.0 

894.3 

85 

70.3 

316.0 

.197 

5.07 

287.0 

1178.3 

891.3 

90 

75.3 

320.0 

.208 

4.81 

291.2 

1179.6 

888.4 

95 

80.3 

323.9 

.219 

4.57 

295.1 

1180.7 

885.6 

100 

85.3 

327.6 

.230 

4.36 

298.9 

1181.8 

882.9 

110 

95.3 

334.5 

.251 

3.98 

306.1 

1184.0 

877.9 

120 

105.3 

341.0 

.272 

3.67 

312.8 

1185.9 

873.2 

130 

115.3 

347.1 

.294 

3.41 

319.1 

1187.8 

886.7 

140 

125.3 

352.8 

.315 

3.18 

325.0 

1189.5 

864.6 

150 

135.3 

358.2 

.336 

2.98 

330.6 

1191.2 

860.6 

160 

145.3 

363.3 

.357 

2.80 

335.9 

1192.7 

856.9 

170 

155.3 

368.2 

.378 

2.65 

340.9 

1194.2 

853.3 

180 

165.3 

372.8 

.398 

2.51 

345.8 

1195.7 

849.9 

190 

175.3 

377.3 

.419 

2.39 

350.4 

1197.0 

846.6 

200 

185.3 

381.6 

.440 

2.27 

354.9 

1198.3 

843.4 

210 

195.3 

385.7 

.461 

2.17 

359.2 

1199.6 

840.4 

220 

205.3 

389.7 

.485 

2.06 

362.2 

1200.8 

838.6 

230 

215.3 

393.6 

.506 

1.98 

366.2 

1202.0 

835.8 

240 

225.3 

397.3 

.527 

1.90 

370.0 

1203.1 

833.1 

250 

235.3 

400.9 

.548 

1.83 

373.8 

1204.2 

830.5 

300 

285.3 

417.4 

.651 

1.535 

390.9 

1209.2 

818.3 

400 

385.3 

444.9 

.857 

1.167 

419.8 

1217.7 

797.9 

500 

485.3 

467.4 

1.062 

.942 

443.5 

1224.5 

781.0 

600 

585.3 

486.9 

1.266 

.790 

464.2 

1230.5 

766.3 

700 

685.3 

504.1 

1.470 

.680 

482.4 

1235.7 

753.3 

800 

785.3 

519.6 

1.674 

.597 

498.9 

1240.3 

741.4 

900 

885.3 

533.7 

1.878 

.532 

514.0 

1244.7 

730.6 

950 

935.3 

540.3 

1.980 

.505 

521.3 

1246.7 

725.4 

1000 

985.3 

546.8 

2.082 

.480 

528.3 

1248.7 

720.3 

324 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


II.  PROPERTIES   OF  SATURATED  STEAM. 


Absolute 
Pressure 
per 
Square 
Inch. 

Temper- 
atures. 

Total 
Latent 
Heat  of 
Steam 
from 
Water 
Supplied 

Water  Heat 
of  Steam 
(to  Raise 
Tempera- 
ture of 
Water  from 
32°  F.). 

Total  Heat 
of  One 
Pound  of 
Steam  from 
Water 
Supplied 
at  32°  F. 

Density 
or  Weight 
of  One 
Cubic  Foot 
of  Steam. 

Volume 
of  One 
Pound  of 
Steam. 

Relative 
Volume, 
or  Cubic 
Feet  of 
Steam 
from  One 
Cubic  Foot 

at  32°  F. 

of  Water. 

Lbs. 

0  Fahr. 

B.t.u. 

B.t.u. 

B.t.u. 

Lbs. 

Cu.  Ft. 

Rel.  Vol. 

122 

342  .4 

872.8 

313.0 

1185.8 

0.2781 

3.595 

224.2 

123 

343.0 

872.3 

313.7 

1186.0 

.2803 

3.567 

222.4 

124 

343.6 

871.9 

314.3 

1186.2 

.2824 

3.541 

220.8 

125 

344.2 

871.5 

314.9 

1186.4 

.2846 

3.514 

219.1 

126 

344.8 

871.1 

315.5 

1186.6 

.2867 

3.488 

217/5 

127 

345.4 

870.7 

316.1 

1186.8 

.2889 

3.462 

215.8 

128 

346.0 

870.2 

316.7 

1186.9 

.2910 

3.436 

214.3 

129 

346.6 

869.8 

317.3 

1187.1 

.2931 

3.411 

212.7 

130 

347.2 

869.4 

317.9 

1187.3 

.2951 

3.388 

211.3 

131 

347.8 

869.0 

318.5 

1187.5 

.2974 

3.362 

209.7 

132 

348.3 

868.6 

319.0 

1187.6 

.2996 

3.338 

208.1 

133 

348.9 

868.2 

319.6 

1187.8 

.3017 

3.315 

206.7 

134 

349.5 

867.8 

320.2 

1188.0 

.3038 

3.291 

205.2 

135 

350.1 

867.4 

320.8 

1188.2 

.3060 

3.268 

203.8 

136 

350.6 

867.0 

321.3 

1188.3 

.3080 

3.246 

202.4 

137 

351.2 

866.6 

321.9 

1188.5 

.3102 

3.224 

201.0 

138 

351.8 

866.2 

322.5 

1188.7 

.3123 

3.201 

199.6 

139 

352.4 

865.8 

323.1 

1188.9 

.3145 

3.180 

198.3 

140 

352.9 

865.4 

323.6 

1189.0 

.3166 

3.159 

197.0 

141 

353.5 

865.0 

324.2 

1189.2 

.3187 

3.138 

195.6 

142 

354.0 

864.6 

324.8 

1189.4 

.3209 

3.117 

194.3 

143 

354.5 

864.2 

325.4 

1189.6 

.3230 

3.096 

193.1 

144 

355.0 

863.9 

325.8 

1189.7 

.3251 

3.076 

191.8 

145 

355.6 

863.5 

326.4 

1189.9 

.3272 

3.056 

190.6 

146 

356.1 

863.1 

326.9 

1190.0 

.3293 

3.037 

189.4 

147 

356.7 

862.7 

327.5 

1190.2 

.3315 

3.017 

188.1 

148 

357.2 

862.3 

328.0 

1190.3 

.3336 

2.998 

186.9 

149 

357.8 

861.9 

328.6 

1190.5 

.3357 

2.979 

185.7 

150 

358.3 

861.5 

329.2 

1190.7 

.3378 

2.960 

184.6 

151 

359.0 

861.1 

329.8 

1190.9 

.3400 

2.941 

183.4 

152 

359.5 

860.7 

330.3 

1191.0 

.3421 

2.923 

182.2 

153 

360.0 

860.4 

330.8 

1191.2 

.3442 

2.905 

181.2 

154 

360.5 

860.0 

331.4 

1191.4 

.3463 

2.887 

180.0 

155 

361.1 

859.6 

331.9 

1191.5 

.3484 

2.870 

179.0 

156 

361.6 

859.2 

332.5 

1191.7 

.3505 

2.8f3 

177.9 

157 

362.1 

858.9 

332.9 

1191.8 

.3527 

2.836 

176.8 

158 

362.6 

858.5 

333.5 

1192.0 

.3548 

2.818 

175.7 

159 

363.1 

858.1 

334.0 

1192.1 

.3569 

2.802 

174.7 

160 

363.6 

857.8 

334.5 

1192.3 

.3590 

2.785 

173.7 

165 

366.0 

856.2 

336.7 

1192.9 

.3696 

2.706 

168.7 

170 

368.2 

854.5 

339.2 

1193.7 

.3801 

2.631 

164.1 

175 

370.8 

852.9 

341.5 

1194.4 

.3905 

2.5£9 

159.7 

180 

372.9 

851.3 

343.8 

1195.1 

.4011 

2.493 

155.5 

185 

375.3 

849.6 

346.2 

1195.8 

.4115 

2.430 

151.5 

190 

377.5 

848.0 

348.5 

1196.5 

.4220 

2.370 

147.8 

195 

379.7 

846.5 

350.7 

1197.2 

.4324 

2.313 

144.2 

200 

381.7 

845.0 

352.8 

1197.8 

.4419 

2.263 

141.1 

STEAM. 


325 


The  rate  at  which  stearn  is  evaporated  in  a  given  boiler  will 
depend  to  a  considerable  extent  upon  the  temperature  at  which 
the  feed-water  enters  it.  The  table  on  page  331  will  illustrate  this 
fact  clearly  and  demonstrates  the  value  of  preheating  feed-water 
in  an  economizer  or  otherwise. 


B.     STEAM-BOILER  PRACTICE. 

Fuels. — There  is  a  large  variety  of  fuels  adapted  for  steam- 
raising.  Possibly  the  first  hi  order  of  precedence  is  wood,  which  is 
equal  to  40  per  cent,  of  its  weight  of  coal,  or  2.5  Ibs.  of  wood  equal 
1  Ib.  of  coal.  Some  say  2.25  Ibs.  of  dry  wood  equal  1  Ib.  of  good 
coal.  The  table  here  presented  gives  a  comparison  of  some  of  the 
usual  fireplace  woods. 

.-.":  ......  •  Weight,Lb,    <*£$£ 

One  cord  of  hickory  or  hard  maple 4500  2000 

"      "      "  white  oak 3850  1711 

"      "      "  beech,  red  oak,  black  oak 3250  1445 

"      "      "  poplar,  chestnut,  elm 2350  1044 

"      "      "pine 2000  890 

Sharpless  assumes  a  coal  equivalent  of  about  10  per  cent,  less  than 
that  given  above. 

Coal  and  other  solid  fuels  vary  considerably  in  composition,  as 
shown  by  these  average  examples: 


ANALYSES  OF  FUELS. 


Water. 

Volatile 
Matter. 

Fixed 
Carbon. 

Ash. 

Sulphur. 

Anthracite  (mixed).  .  . 
Semi-bituminous  
Bituminous  

3.40 
1.00 
1.20 

3.80 
20.00 
32.50 

83.80 
73.00 
60.00 

8.40 
5.00 
5.30 

0.60 
1.00 
1  00 

T  ignite  . 

22.00 

32.00 

37.00 

9  00 

~*oke  .       

89  .  00 

10  00 

0  80 

Carbon. 

Hydrogen. 

Oxygen. 

Nitrogen. 

Ash. 

Vood   dry 

50  0 

6  0 

41   0 

1   0 

2  0 

Charcoal  ...           .... 

75  5 

2  5 

12  0 

1  0 

Peat,  dry  and  ash-free 

58.0 

5.7 

35.0 

1.2 

326 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


WEIGHT   PER   CUBIC    FOOT   OF  COAL   AND   COKE. 

Lbs.  per  Storage  for 

Cu.  Ft.  Long  Ton. 

Anthracite  coal,  market  sizes,  loose 52-56  40-43  cu.  ft. 

Anthracite  coal,  market  sizes,  moderately 

shaken "  56-60 

Anthracite    coal,    market    size,    heaped 

bushel,  loose 77-83 

Bituminous  coal,  broken,  loose 47-52  43-48     " 

Bituminous  coal ,  moderately  shaken  ....   50-56 

Bituminous  coal,  heaped  bushel 70-78 

Dry  coke 23-32  80-97     " 

Dry  coke,  heaped  bushel  (average  38).. .  35-42 

HEATING  VALUE  OF  SOME  FUELS. 

B.t.u. 

Peat,  Irish,  perfectly  dried,  ash  4  per  cent 10,200 

Peat,  air-dried,  25  per  cent,  moisture,  ash  4  per  cent 7,400 

Wood,  perfectly  dry,  ash  2  per  cent 7,800 

Wood,  25  per  cent,  moisture 5,800 

Tanbark,  perfectly  dry,  15  per  cent,  ash 6,100 

Tanbark,  30  per  cent,  moisture 4,300 

Straw,  10  per  cent,  moisture,  ash  4  per  cent 5,450 

Straw,  dry,  ash  4  per  cent 6,300 

Lignites 11,200 

The  above  are  approximate  figures,  for  on  such  materials 
qualities  are  very  variable. 

Coal  ard  coke  are  often  measured  by  the  bushel.  The  stand- 
ard bushel  of  the  American  Gaslight  Association  is  18J  in.  diam. 
and  8  in.  deep  =  2150.42  cu.  i~.  A  Iraped  bushel  is  the  samo  plus 
a  ccne  19£  in.  diam.  and  6  in.  high,  or  a  total  of  2747.7  cu.  in. 
An  ordinary  heaped  bushel  =  1J  struck  bushels  =  2688  cu.in.  =  10 
gallons  dry  measure. 

Crude  petroleum  =  7.3  Ibs.  per  gallon. 

ANTHRACITE-COAL  SIZES. 


Size  and  Name. 


Chestnut 

Pea 

No.  1  buckwheat 

"'  2  "  or  rice.  .. 
"3  "  or  barley. 
Dust. . 


Through  a  Round  Hole. 


\\  inches  diameter 


Over  a  Round  Hole. 
•£  inches  diameter 


STEAM. 


327 


Comparative  Values  of  Fuel. — The  following  table  shows  the 
relative  values  of  fuel  used  in  furnace  practice,  either  coal  or  coke, 
with  different  percentages  of  ash,  showing  the  influence  of  the 
latter. 


h 

|u 

F 

75 
76 
77 
78 
79 
80 
81 
82 
83 
84 
85 
86 
87 
88 
89 
90 
91 
92 
98 

Percentage  of  Ash. 

2% 

3% 

4% 

5% 

6% 

7% 

8% 

9% 

$2.81: 

2.86 
2.90 
2.93 
2.96 
3.00 
3.04 

10% 

11% 

$2.79 
2.83 
2.87 
2.88 
2.92 
2.96 
3  00 

12% 

$2.77 
2.81 
2.85 
2.86 
2.90 
2.94 
2.98 

13% 

$2.76 
2.79 
2.84 
2.84 
2.88 
2.92 

14% 

$2.74 
2.78 
2.82 

$2.83 
2.88 
2.91 
2.95 
2.97 
3.02 
306 

§2.80 
2.84 
2.88 
2.90 
2.94 
2.98 
302 

$2.93 
2.97 
2.99 
3.04 
308 

S3.01 
3.06 
3.10 

$3.17 
3.21 
3.25 
3.3] 
3.35 
3.39 
3.42 
3.45 
3.50 
3.54 
3.57 
3.6] 

3.15 
3.19 
3.23 
3.29 
3.33 
3.37 
3.39 
3.43 
3.48 
3.52 

3.13 
3.17 
3.21 
3.26 
3.30 
3.34 
3.36 
3.41 

3.10 
3.14 
3.18 
3.23 
3.27 
3.32 
3.33 

3.0F 
3.12 
3.16 
3.20 
3.24 
3.29 

3.06 
3.10 
3.14 
3.18 

3.04 
3.08 
3.12 

3.02 
3.06 

$3^33 
3.37 
3.41 
3.44 
3.47 
3.51 
3.56 
3.59 
3.64 

$3^54 
3.58 
3.63 
3.68 

$3.46 
3.49 
3.52 
3.57 
3.61 
3.66 

Approximately  1.43  to  1.54  Ibs.  of  petroleum  of  7.3  Ibs.  per 
gallon  equals  1  Ib.  best  soft  coal.  It  requires  about  4  per  cent,  of 
the  steam  generated  to  operate  the  atomizing  oil  spray  for  a  boiler, 
this  being  preferred  to  an  air  spray.  Probably  35,000  cu.  ft.  of 
natural  gas  will  be  equal  in  heating  value  to  a  ton  of  coal. 

Water  Supply.  —  The  water-pipe  should  be  ample  in  size,  so  as 
not  to  restrict  the  flow  should  incrustations  form.  Bends  in  the 
pipe  also  reduce  the  delivery.  Weisbach  gives  this  formula  for  the 
loss  due  to  friction: 

T72 

f-— 

64.4' 


172 
P=f—  = 


where  P=loss  in  pressure,  Ibs.  per  sq.  in.; 
V=  velocity  of  flow  in  ft.  per  second; 

/=  coefficient   of  friction  found  in  the  following  table  for 
various  angles  of  bend,  A: 

A..   20°     40°     45°       60°       80°     90°      100°     110°     120°     130° 
/..0.02  0.06  0.079  0.158  0.32  0.426  0.546  0.674  0.806  0.934 


OF  THE 

UNIVERSITY 

OF 


328 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


This  applies  to  such  short  bends  as  are  found  in  ordinary  fittings, 
such  as  90°  and  45°  ells,  tees,  etc.  A  globe  valve  will  produce  a 
loss  about  equal  to  two  90°  bends,  a  straightway  valve  about  equal 
to  one  45°  bend.  To  use  the  above  formula  find  the  velocity  V 
from  the  table,  square  this  speed,  and  divide  the  result  by  64.4; 
multiply  the  quotient  by  the  tabular  value  of  F,  corresponding  to 
the  angle  of  the  turn  A. 

For  example,  a  400-h.p.  battery  of  boilers  is  to  be  fed  through 
a  2-in.  pipe.  Allowing  for  fluctuations  we  figure  40  gallons  per 
minute,  making  244  feet  per  minute  speed,  equal  to  a  velocity  of 
4.06  ft.  per  second.  Suppose  our  pipe  is  in  all  75  ft.  long,  we  have 
from  the  second  table  on  page  329,  for  40  gallons  per  minute,  1.6 
Ibs.  loss;  for  75  ft.  we  have  only  75  per  cent,  of  this,  =1.2  Ibs. 
Suppose  we  have  six  right-angled  ells,  each  giving  F= 0.426.  We 
have  then  4.06X4.06=  16.48;  divide  this  by  64.4  =  0.256.  Multiply 
this  by  F= 0.426  lb.,  and  as  there  are  six  ells,  multiply  again  by  6, 
and  we  have  6X0.426X0.256=0.654.  The  total  friction  in  the  pipe 
is  therefore  1.2+0.654  Ibs.  per  sq.  in.  If  the  boiler  pressure  is  100 
Ibs.  and  the  water-level  in  the  boiler  is  8  feet  higher  than  the  pump- 
suction  level  we  have  first  8X0.433  =  3.464  Ibs.  The  total  pres- 
sure on  the  pump-plunger  then  is  100  +  3.464  +  1.854=105.32  Ibs. 
per  sq.  in.  If  in  place  of  six  right-angled  ells  we  had  used  three 
45°  ells,  they  would  have  cost  us  only  3X0.079=0.237  lb.;  0.237X 
0.256=0.061. 

The  total  friction  head  would  have  been  1.20+0.061  =  1.261 
and  the  total  pressure  on  the  plunger  100+3.464  +  1.261  =  104.73 
Ibs.  per  sq.  in.,  a  saving  over  the  other  plan  of  nearly  0.6  lb. 

To  be  accurate  we  ought  to  add  a  certain  head  in  either  case 
"to  produce  the  velocity."  But  this  is  very  small,  being  for 
velocities  of: 


2 
0.027 

3 

0.061 

4 

0.108 

5 

0.168 

6 
0.244 

8 
0.433 

10 
0.672 

12  and 
0  .  970  and 

18  feet  per  sec. 
2.  18  Ibs.  per  sq.  in. 

Our  results  should  therefore  have  been  increased  by  about  0.11 
Ibs.  It  is  usual,  however,  to  use  larger  pipes  and  thus  to  materially 
reduce  the  frictional  losses. 

The  weight  of  water  varies  with  the  temperature  as  given  by 
the  table  by  C.  A.  Smith  on  page  330. 


STEAM. 


329 


TABLE  GIVING  RATE  OF  FLOW  OF  WATER,  IN  FEET  PER  MINUTE,  THROUGH 
PIPES  OF  VARIOUS  SIZES,   FOR  VARYING  QUANTITIES  OF  FLOW. 


Gallons 

Diamete 

",  Inches. 

per 
Minute. 

1 

1 

H 

ii 

2 

Zi 

3 

4 

5 

218 

122.5 

78.5 

54.5 

30.5 

19.5 

13.5 

7.6 

10 

436 

245 

157 

109 

61 

38 

27 

15.3 

15 

653 

367.5 

235.5 

163.5 

91.5 

58.5 

40.5 

23 

20 

872 

490 

314 

218 

122 

78 

54 

30.6 

25 

1090 

612.5 

392.5 

272.5 

152.5 

97.5 

67.5 

38.3 

30 

.... 

735 

451 

327 

183 

117 

81 

46 

35 

857.5 

549.5 

381.5 

213.5 

136.5 

94.5 

53.6 

40 

980 

628 

436 

244 

156 

108 

61.3 

45 

.... 

1102.5 

706.5 

490.5 

274.5 

175.5 

121.5 

69 

50 

785 

545 

305 

195 

135 

76.6 

75 

1177.5 

817.5 

457.5 

292.5 

202.5 

115 

100 

1090 

610 

380 

270 

153.3 

125 

762.5 

487.5 

337.5 

191.6 

150 

915 

585 

405 

230 

175 

1067.5 

682.5 

472.5 

268.5 

200 

1220 

780 

540 

306.6 

LOSS  IN  PRESSURE  DUE  TO  FRICTION. 
POUNDS  PER  SQUARE  INCH  FOR  PIPE  100  FEET  LONO. 


Gallons 
Dis- 
charged 

Diameter 

,  Inches. 

per 
Minute. 

* 

1 

H 

11 

2 

2| 

3 

4 

5 

3.3 

0.84 

0.31 

0.12 

10 

13.0 

3.16 

1.05 

0.47 

0.12 

15 

28.7 

6.98 

2.38 

0.97 

20 

50.4 

12.3 

4.07 

1.66 

0.42 

25 

78.0 

19.0 

6.40 

2.62 

0.21 

0.10 

30 

.... 

27.5 

9.15 

3.75 

O.Q1 

35 

.... 

37.0 

12.4 

5.05 

40 

.... 

48.0 

16.1 

6.52 

1.60 

45 

20.2 

8.15 

50 

.  .  '.  '. 

24.9 

10.0 

2.44 

0.81 

0.33 

0.09 

75 

56.1 

22.4 

5.32 

1.80 

0.74 

100 

39.0 

9.46 

3.20 

1.31 

0.33 

125 

14.9 

4.89 

1.99 

150 

21.2 

7.0 

2.85 

0.69 

175 

28.1 

9.46 

3.85 

200 

37.5 

12.47 

5.02 

1.22 

330 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


WEIGHT  OF  WATER  PER  CUBIC  FOOT  AND  HEAT-UNITS  IN  WATER 
BETWEEN    32°     AND   212°   F. 


Weight 

Weight 

Weight 

in 

in 

in 

Temp., 

Pounds 

Heat- 

Temp., 

Pounds 

Heat- 

Temp., 

Pounds 

Heat- 

Deg.  F. 

per 
Cubic 

units. 

Deg.  F. 

Cubic 

units. 

Deg.  F. 

per 
Cubic 

units. 

Foot. 

Foot. 

Foot. 

32 

62.42 

0.00 

96 

62.07 

64.07 

160 

60.98 

128.37 

34 

62.42 

2.00 

98 

62.05 

66.07 

162 

60.94 

130.39 

36 

62.42 

4.00 

100 

62.02 

68.08 

164 

60.90 

132.41 

38 

62.42 

6.00 

102 

62.00 

70.09 

166 

60.85 

134.42 

40 

62.42 

8.00 

104 

61.97 

72.09 

168 

60.81 

136.44 

42 

62.42 

10.00 

106 

61.95 

74.10 

170 

60.77 

138.45 

44 

62.42 

12.00 

108 

61.92 

76.10 

172 

60.73 

140.47 

46 

62.42 

14.00 

110 

61.89 

78.11 

174 

60.68 

142.49 

48 

62.41 

16.00 

112 

61.86 

80.12 

176 

60.64 

144.51 

50 

62.41 

18.00 

114 

61.83 

82.13 

178 

60.59 

146.52 

52 

62.40 

20.00 

116 

61.80 

84.13 

180 

60.55 

148.54 

54 

62.40 

22.01 

118 

61.77 

86.14 

182 

60.50 

150.56 

56 

62.39 

24.01 

120 

61.74 

88.15 

184 

60.46 

152.58 

58 

62.38 

26.01 

122 

61.70 

90.16 

186 

60.41 

154.60 

60 

62.37 

28.01 

124 

61.67 

92.17 

188 

60.37 

156.62 

62 

62.36 

30.01 

126 

61.63 

94.17 

190 

60.32 

158.64 

64 

62.35 

32.01 

128 

61.60 

96.18 

192 

60.27 

160.67 

66 

62.34 

^34.  02 

130 

61.56 

98.19 

194 

60.22 

162.69 

68 

62.33 

36.02 

132 

61.52 

100.20 

196 

60.17 

164.71 

70 

62.31 

38.02 

134 

61.49 

102.21 

198 

60.12 

166.73 

72 

62.30 

40.02 

136 

61.45 

104.22 

200 

60.07 

168.75 

74 

62.28 

42.03 

138 

61.41 

106.23 

202 

60.02 

170.78 

76 

62.27 

44.03 

140 

61.37 

108.25 

204 

59.97 

172.80 

78 

62.25 

46.03 

142 

61.34 

110.26 

206 

59.92 

174.83 

80 

62.23 

48.04 

144 

61.30 

112.27 

208 

59.87 

176.85 

82 

62.21 

50.04 

146 

61.26 

114.28 

210 

59.82 

178.87 

84 

62.19 

52.04 

148 

61.22 

116.29 

212 

59.76 

180.90 

86 

62.17 

54.05 

150 

61.18 

118.31 

88 

62.15 

56.05 

152 

61.14 

120.32 

90 

62.13 

58.06 

154 

61.10 

122.33 

92 

62.11 

60.06 

156 

61.06 

124.35 

94 

62.09 

62.06 

158 

61.02 

126.36 

STEAM. 


331 


Pure  water  at  62  deg.  F.  weighs  62.355  Ibs.  per  cu.  ft.,  or  8£ 
Ibs.  per  U.  S.  gallon;  7.48  gallons=  1  cu.  ft.  It  takes  30  Ibs.  or  3.6 
gallons  of  boiler  feed-water  for  each  horse-power  per  hour. 

HEAT  TRANSMITTED  BY  CONDENSER  SURFACES  PER  SQUARE 
FOOT  PER  HOUR. 

Surface.  B.t.u. 

Smooth  vertical  plane 406 

Vertical  plane  with  about  80%  surface  in  ribs  or  cor- 
rugations    170 

Smooth  vertical  pipe  surface 480 

Vertical  tube  with  67%  of  surface  in  corrugations.  . .  221 

Horizontal  smooth  tube  or  pipe 369 

Horizontal  tube  with  67%  of  surface  in  corrugations  185 

Note. — This  table  is  correct  for  steam  of  15  to  22  Ibs.  pres- 
sure ;  for  exhaust-steam  reduce  in  proportion  to  temperature,  except 
for  corrugated  and  ribbed  surfaces,  which  lose  very  rapidly  for 
low  steam  temperatures.  For  hot  water,  50  per  cent,  of  the  tabular 
numbers  is  approximately  correct. 

PERCENTAGE    OF   SAVING    FOR   EACH    DEGREE    OF   INCREASE   IN   TEM- 
PERATURE  OF   FEED-WATER   HEATED. 


Initial 
Tempera- 
ture of 
Feed. 

Pressure  of  Steam  in  Boiler,  Lbs.  per  Sq.  In.  above  Atmosphere. 

0 

20 

40 

60 

80 

100 

120 

140 

160 

180 

200 

32° 

.0872 

.0861 

.0855 

.0851 

.0847 

.0844 

.0841 

.0839 

.0837 

.0835 

.0833 

40 

.0878 

.0867 

.0861 

.0856 

.0853 

.0850 

.0847 

.0845 

.0843 

.0841 

.0839 

50 

.0886 

.0875 

.0868 

.0864 

.0860 

.0857 

.0854 

.0852 

.0850 

.0848 

.0846 

60 

.0894 

.0883 

.0876 

.0872 

.0867 

.0864 

.0862 

.0859 

.0856 

.0855 

.0853 

70 

.0902 

.0890 

.0884 

.0879 

.0875 

.0872 

.0869 

.0867 

.0864 

.0862 

.0860 

80 

.0910 

.0898 

.0891 

.0887 

.0883 

.0879 

.0877 

.0874 

.0872 

.  0870 

.0868 

90 

.0919 

.0907 

.0900 

.0895 

.0888 

.0887 

.0884 

.0883 

.  0879 

.0877 

.0875 

100 

.0927 

.0915 

.0908 

.0903 

.0899 

.0895 

.0892 

.0890 

.0887 

.0885 

.0883 

110 

.0936 

.0923 

.0916 

.0911 

.0907 

.0903 

.0900 

.0898 

.0895 

.0893 

.0891 

120 

.0945 

.0932 

.0925 

.0919 

.0915 

.0911 

.0908 

.0906 

.0903 

.0901 

.0899 

130 

.0954 

.0941 

.0934 

.0928 

.0924 

.0920 

.0917 

.0914 

.0912 

.0909 

.0907 

140 

.0963 

.0950 

.0943 

.0937 

.0932 

.0929 

.0925 

.0923 

.0920 

.0918 

.0916 

150 

.0973 

.0959 

.0951 

.0946 

.0941 

.0937 

.0934 

.0931 

.0929 

.0926 

.0924 

160 

.0982 

.0968 

.0961 

.0955 

.0950 

.0946 

.0943 

.0940 

.0937 

.0935 

.0933 

170 

.0992 

.0978 

.0970 

.0964 

.0959 

.0955 

.0952 

.0949 

.0946 

.0944 

.0941 

180 

.1002 

.0988 

.0981 

.0973 

.0969 

.0965 

.0961 

.0958 

.  0955 

.0953 

.0951 

190 

.1012 

.0998 

.0989 

.0983 

.0978 

.0974 

.0971 

.0968 

.0964 

.0962 

.0960 

200 

.1022 

.1008 

.0999 

.0993 

.0988 

.0984 

.0980 

.0977 

.0974 

.0972 

.0969 

210 

.1033 

.1018 

.1009 

.1003 

.0998 

.0994 

.0990 

.0987 

.0984 

.0981 

.0979 

220 

.1029 

.1019 

.1013 

.1008 

.1004 

.1000 

.0997 

.0994 

.0991 

.0989 

230 

.1039 

.1031 

.1024 

.1018 

.1012 

.1010 

.1007 

.1003 

.1001 

.0999 

240 

.  1050 

.1041 

.  1034 

.1029 

.1024 

.1020 

.1017 

.1014 

.1011 

.1009 

250 

.1062 

.1052 

.1045 

.1040 

.1035 

.1031 

.1027 

.1025 

.1022 

.1019 

332 


AMERICAN   GAS-ENGINEERING  PRACTICE. 


MAXIMUM  HEIGHT  WATER  CAN   BE  LIFTED  BY  SUCTION  AT  VARIOUS 
DISTANCES   ABOVE   SEA-LEVEL. 


Height  Above  Sea- 
level,  in  Feet. 

Average  Barometric  Pressure. 

Height  of  Lift,  Feet. 

Inches. 

Lbs.  per  Sq.  In. 

0 

30.00 

14.7 

33.9 

100 

29.89 

14.6 

33.8 

200 

29.78 

14.6 

33.7 

300 

29.68 

14.5 

33.6 

400 

29.57 

14.5 

33.5 

500 

29.46 

14.4 

33.3 

600 

29.35 

14.4 

33.2 

700 

29.25 

14.3 

33.1 

800 

29.14 

14.3 

32.0 

900 

29.04 

14.2 

32.9 

1000 

28.94 

14.2 

32.7 

1250 

28.67 

14.1 

32.4 

1500 

28.42 

13.9 

32.1 

2000 

27.91 

13.7 

31.6 

2500 

27.40 

13.4 

31.0 

3000 

26.92 

13.2 

30.4 

3500 

26.43 

13.0 

29.9 

4000 

25.96 

12.7 

29.4 

4500 

25.49 

12.5 

28.9 

5000 

25.02 

12.3 

28.3 

6000 

24.12 

11.8 

27.3 

7000 

23.28 

11.4 

26.3 

8000 

22.44 

11.0 

25.4 

9000 

21.64 

10.6 

24.5 

10000 

20.85 

10.2 

23.6 

Note. — The  heights  given  above  are  for  a  perfect  vacuum.     In  practice, 
pumps  will  ordinarily  lift  water  about"  eight-tenths  the  height  given. 


CHIMNEYS. 

The  "  proportions  of  chimneys  "  vary  very  much  according  to 
the  requirements.  Every  chimney  should  be  large  enough  in 
cross-section  to  carry  off  the  gases  and  high  enough  to  produce 
sufficient  draught  to  cause  a  rapid  combustion.  The  object  of  a 
chimney  being  to  carry  off  the  waste  gases,  it  naturally  determines 
the  amount  of  fuel  that  can  be  burnt  per  hour,  and  it  is  advisable 
to  have  invariably  a  good  draught,  as  it  can  always  be  regulated  by 
a  damper. 

.Draught  pressure  is  caused  by  the  difference  in  weight  between  a 
column  of  hot  gases  in  the  chimney  and  a  column  of  air  of  equal 
height  and  area  outside  the  chimney. 


STEAM.  333 

Formula  for  finding  the  force  of  draught  in  inches  of  water  for 
any  given  chimney : 

7.64     7.95N 


where  F  =  force  of  draught  in  inches  of  water; 
H  =  height  of  chimney  in  feet; 
TI  =  absolute  temperature  of  chimney  gases  (t  +  460) ; 
T2=  "  the  external  air  ( 

t  =  temperature  of  chimney  gases; 

ti=  "  "  external  air. 

Formula  for  finding  the  height  of  a  chimney  in  feet  for  a  given 
force  of  draught: 


/7.64    7.95V 
\  T,  ~  Tj 


To  find  the  maximum  force  of  draught  for  any  given  chimney, 
the  external  air  being  60  deg.  F.  and  the  heated  column  being 
600  deg.  F.,  multiply  the  height  above  the  grate  in  feet  by  0.0073, 
and  the  product  is  the  force  of  draught  expressed  in  inches  of  water. 

William  Kent,  in  his  " Mechanical  Engineer's  Pocket-book" 
(pages  734  and  736,  4th  Revised  Ed.),  gives  the  following: 

"  The  sizes  corresponding  to  the  given  commercial  horse-powers 
are  believed  to  be  ample  for  all  cases  in  which  the  draught  areas 
through  the  boiler-flues  and  connections  are  sufficient,  say  rot  less 
than  twenty  per  cent,  greater  than  the  area  of  the  chimney,  and 
in  which  the  draught  between  the  boilers  and  chimney  is  not 
checked  by  long  horizontal  passages  ard  right-angled  bends." 

Note  that  the  figures  in  table  p.  336  correspond  to  a  coal  con- 
sumption of  5  Ibs.  coal  per  horse-power  hour.  This  liberal  allowance 
is  made  to  cover  the  contingencies  of  poor  coal  being  used,  and 
of  boilers  being  driven  beyond  their  rated  capacity.  In  large 
plants  with  economical  boilers  and  engines,  good  fuel,  and  other 
favorable  conditions,  which  will  reduce  the  maximum  rate  of  coal 
consumption  at  any  one  time  to  less  than  5  Ibs.  per  h.p.  per  hour, 
the  figures  in  the  table  may  be  multiplied  by  the  ratio  of  five  to 
the  maximum  expected  coal  consumption  per  horse-power  per 
hour.  Thus,  with  conditions  which  make  the  maximum  coal 
consumption  2.5  Ibs.  per  hour,  the  chimney  300  ft.  high X 12  ft. 
diameter  should  be  sufficient  for  6155X2=  12,310  h.p.  The  formula 
is  based  on  the  following  data. 

Chimney  Draught. — According  to  the  data  of  the  Green  Fuel 
Economizer  Co.: 


334  AMERICAN  GAS-ENGINEERING  PRACTICE. 

1.  The  draught  power  of  the  chimney  varies  as  the  square  root 
of  the  height. 

2.  The  retarding  of  the  ascending  gases  by  friction  may  be 
considered  as  equivalent  to  a  diminution  of  the  area  of  the  chimney, 
or  to  a  lining  of  the  chimney  by  a  layer  of  gas  which  has  no  velocity. 
The  thickness  of  this  lining  is  assumed  to  be  2  ins.  for  all  chimneys, 
or  the  diminution  of  area  equal  to  the  perimeter  X  2  ins.  (neglecting 
the  overlapping  of  the  corners  of  the  lining).     Let  D=  diameter 
in  feet,  J.  =  area,  and  E=  effective  area  in  square  feet. 

or\  o        _ 

For  square  chimneys,  E=D2  —  —=A  —  —\//A. 
For  round  chimneys,  E= 

For  simplifying  calculations,  the  coefficient  of  V  A  may  be 
taken  as  0.6  for  both  square  and  round  chimneys,  and  the  formula 
becomes 


3.  The  power  varies  directly  as  this  effective  area  E. 

4.  A  chimney  should  be  proportioned  so  as  to  be  capable  of 
giving  sufficient  draught  to  cause  the  boiler  to  develop  much  more 
than  its  rated  power,  in  case  of  emergencies,  or  to  cause  the  com- 
bustion of  5  Ibs.  of  fuel  per  rated  horse-power  of  boiler  per  hour. 

5.  The  power  of  the  chimney  varying  directly  as  the  effective 
area  E,  and  as  the  square  root  of  the  height  H,  the  formula  for 
horse-power  of  boiler  for  a  given  size  of  chimney  will  take  the 
form  h.p.  =  CM///,  in  which  C  is  a  constant,  the  average  value  of 
which,  obtained  by  plotting  the  results  obtained  from  numerous 
examples  in  practice,  the  author  finds  to  be  3.33. 

The  formula  for  horse-power  then  is 


h.p.  =  3.33tfv#,     or    h.p.  = 

If  the  horse-power  of  boiler  is  given,  to  find  the  size  of  chimney, 
the  height  being  assumed, 


vH 

For  round  chimneys,  diameter  of  chimney  =  diameter  of  E+4  ins. 

For  square  chimneys,  side  of  chimney  =  v/#  +  4  ins. 

If  effective  area  E  is  taken  in  square  feet,  the  diameter  in  inches 


STEAM.  335 

is  d=  13.54\/J£  +  4  ins.;  and  the  side  of  a  square  chimney  in  inches 
is  s=12V/£r+4  ins. 

If  horse-power  is  given  and  area  assumed,  the  height 


In  proportioning  chimneys  the  height  is  generally  first  assumed, 
with  due  consideration  to  the  heights  of  surrounding  buildings 
or  hills  near  to  the  proposed  chimney,  the  length  of  horizontal 
flues,  the  character  of  coal  to  be  used,  etc.,  and  then  the  diameter 
required  for  the  assumed  height  and  horse-power  is  calculated 
by  the  formula  or  taken  from  the  table. 

From  these  formula  the  table  on  page  336  has  been  calculated, 
assuming  that  for  each  horse-power  5  Ibs.  of  coal  are  burned  per 
hour. 

WEIGHT  OF  COAL  AND  STORAGE. 

21  bushels  coke=l  cubic  yard  (English). 

72  ".  -1  ton. 

Cannel  coal,  45  cubic  feet  per  ton. 
Coal  store  should  equal  six  weeks'  supply. 

SPACE     OCCUPIED     PER     TON     OF     DIFFERENT     COALS. 

Weight  per 
Cubic  Foot. 

Average  anthracite  =  39  cubic  feet     58.25  Ibs. 

bituminous  =43      "      "       53        " 

Navy  allowance  for  storage  =  48      ' '      " 

COKE. 

23  to  32  Ibs.  per  cu.  ft. 
Ton  occupies  from  80  to  97  cu.  ft. 
Coal  in  coking  swells  in  bulk  from  25  to  50  ptr  cent. 
Coke  and  coal    will  evaporate  about  equal  amounts  of  water 
and  about  twice  the  amount  of  an  equal  weight  of  wood. 

COAL — ANTHRACITE . 

Actual  weight  about  93.5  Ibs.  per  cu.  ft. 
Broken  (average)  52  to  60  Ibs.  per  cu.  ft. 
Ton  occupies  from  40  to  43  cu.  ft. 

COAL — BITUMINOUS. 

Actual  weight  about  84  Ibs.  per  cu.  ft. 
Broken  (average)  47  to  56  Ibs.  per  cu.  ft. 
About  70  to  78  Ibs.  per  bu. 
Ton  occupies  43  to  48  cu.  ft. 
Coal  when  broken  increases  in  bulk  up  to  75  per  cent. 


336 


AMERICAN  GAS-ENGINEERING  PRACTICE 


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STEAM. 


FLUE   AREA   REQUIRED    FOR  THE   PASSAGE   OF   A  GIVEN   VOLUME   OF 
AIR  AT  A   GIVEN   VELOCITY. 


Volume  in 
Cubic  Feet 
per  Minute. 

Velocity  in  Feet  per  Minute. 

300 

400 

500 

600 

700 

800 

900 

1000 

1100 

1200 

100 

48 

36 

29 

24 

21 

18 

16 

14 

13 

12 

125 

60 

45 

36 

30 

26 

23 

20 

18 

16 

15 

150 

72 

54 

43 

36 

31 

27 

24 

22 

20 

18 

175 

84 

63 

50 

42 

36 

32 

28 

25 

23 

21 

200 

96 

72 

58 

48 

41 

36 

32 

29 

26 

24 

225 

108 

81 

65 

54 

46 

41 

36 

32 

29 

27 

250 

120 

90 

72 

60 

51 

45 

40 

36 

33 

30 

275 

132 

99 

79 

66 

57 

50 

44 

40 

36 

33 

300 

144 

108 

86 

72 

62 

54 

48 

43 

39 

36 

325 

156 

1x7 

94 

78 

67 

59 

52 

47 

43 

39 

350 

168 

126 

101 

84 

72 

63 

56 

50 

46 

42 

375 

180 

135 

108 

90 

77 

68 

60 

54 

49 

45 

400 

192 

144 

115 

96 

82 

72 

64 

58 

52 

48 

425 

204 

153 

122 

102 

87 

77 

68 

61 

56 

51 

450 

216 

162 

130 

108 

93 

81 

72 

65 

59 

54 

475 

228 

171 

137 

114 

98 

86 

76 

68 

62 

57 

500 

240 

180 

144 

120 

103 

90 

80 

72 

65 

60 

525 

252 

189 

151 

126 

108 

95 

84 

76 

69 

63 

550 

264 

198 

158 

132 

113 

99 

88 

79 

72 

66 

575 

276 

207 

166 

138 

118 

104 

92 

83 

75 

69 

600 

288 

216 

173 

144 

123 

108 

96 

86 

79 

72 

625 

300 

225 

180 

150 

129 

113 

100 

90 

82 

75 

650 

312 

234 

187 

156 

134 

117 

104 

94 

85 

78 

675 

324 

243 

194 

162 

139 

122 

108 

97 

88 

81 

700 

336 

252 

202 

168 

144 

126 

112 

101 

92 

84 

725 

348 

261 

209 

174 

149 

131 

116 

104 

95 

87 

750 

360 

270 

216 

180 

154 

135 

120 

108 

98 

90 

775 

372 

279 

223 

186 

159 

140 

124 

112 

101 

93 

800 

384 

288 

230 

192 

165 

144 

128 

115 

105 

96 

825 

396 

297 

238 

198 

170 

149 

132 

119 

108 

99 

850 

408 

306 

245 

204 

175 

153 

136 

122 

111 

102 

875 

420 

315 

252 

210 

180 

158 

140 

126 

115 

105 

900 

432 

324 

259 

216 

185 

162 

144 

130 

118 

108 

925 

444 

333 

266 

222 

190 

167 

148 

133 

121 

111 

950 

456 

342 

274 

228 

195 

171 

152 

137 

124 

114 

975 

468 

351 

281 

234 

201 

176 

156 

140 

128 

117 

1000 

480 

360 

288 

240 

206 

180 

160 

144 

131 

121 

338 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


FLUE  AREA  REQUIRED  FOR  THE  PASSAGE  OF  A  GIVEN  VOLUME  OF  AIR 
AT   A   GIVEN    VELOCITY— (Continued). 


Volume  in 
Cubic  Feet 
per  Minute. 

Velocity  in  Feet  per  Minute. 

1300 

1400 

1500 

1600 

1700 

1800 

1900 

2000 

2100 

100 

11 

10 

9.6 

9 

8.5 

8 

7.6 

7.2 

6.9 

125 

14 

13 

12 

11.3 

10.6 

10 

9.5 

9 

8.6 

150 

16 

15 

14.4 

13.5 

12.7 

12 

11.4 

10.8 

10.3 

175 

19 

18 

16.8 

15.8 

14.8 

14 

13.3 

12.6 

12 

200 

22 

21 

19.2 

18 

16.9 

16 

15.2 

14.4 

13.7 

225 

25 

23 

21.6 

20.3 

19.1 

18 

17.1 

16.2 

15.6 

250 

28 

26 

24 

22.5 

21.2 

20 

19 

18 

17.1 

275 

30 

28 

26.4 

24.8 

23.3 

22 

21.8 

19.8 

18.9 

300 

33 

31 

28.8 

27 

25.4 

24 

22.7 

21.6 

20.6 

325 

36 

33 

31.2 

29.3 

27.5 

26 

24.6 

23.4 

22.3 

350 

39 

36 

33.6 

31.5 

29.6 

28 

26.5 

25.2 

24 

375 

42 

39 

36 

33.8 

31.8 

30 

28.4 

27 

25.7 

400 

44 

41 

38.4 

36 

33.9 

32 

30.3 

28.8 

27.4 

425 

47 

44 

40.8 

38.3 

36 

34 

32.2 

30.6 

29.1 

450 

50 

46 

43.2 

40.5 

38.1 

36 

34.1 

32.4 

30.9 

475 

53 

49 

45.6 

42.8 

40.2 

38 

36 

34.2 

32.6 

500 

55 

51 

48; 

45 

42.4 

40 

37.9 

36 

34.3 

525 

58 

54 

50.4 

47.3 

44.5 

42 

39.8 

37.8 

36 

550 

61 

57 

52.8 

49.5 

40.6 

44 

41.7 

38.6 

37.7 

575 

64 

59 

55.2 

51.8 

48.7 

46 

43.6 

41.4 

39.4 

600 

66 

62 

57.6 

54 

50.8 

48 

45.5 

43.2 

41.1 

625 

69 

64 

60 

56.3 

52.9 

50 

47.4 

45 

42.9 

650 

72 

67 

62.4 

58.5 

55.1 

52 

49.3 

46.8 

44.6 

675 

75 

69 

64.8 

60.8 

57.2 

54 

51.2 

48.6 

46.3 

700 

78 

72 

67.2 

63 

59.3 

56 

53.1 

50.4 

48 

725 

80 

75 

69.6 

65.3 

61.4 

58 

55 

52.2 

49.7 

750 

83 

77 

72 

67.5 

63.5 

60 

56.9 

54 

51.4 

775 

86 

80 

74.4 

69.8 

65.6 

62 

58.8 

56.3 

53.1 

800 

89 

82 

76.8 

72 

67.8 

64 

60.6 

57.6 

54.9 

825 

91 

85 

79.2 

74.3 

69.9 

66 

62.5 

59.4 

56.6 

850 

94 

87 

81.6 

76.5 

72 

68 

64.4 

61.2 

58.4 

875 

97 

90 

84 

78.8 

74 

70 

67.3 

63 

60 

900 

100 

93 

86.4 

81 

76.2 

.  72 

68.2 

64.8 

61.7 

925 

103 

95 

88.8 

83.3 

78.4 

74 

70.1 

66.6 

63.4 

950 

105 

98 

91.2 

85.5 

80.5 

76 

72 

68.4 

65.1 

975 

108 

100 

93.6 

87.8 

82.6 

78 

73.9 

70.2 

66.8 

1000 

111 

103 

96 

90 

84.7 

80 

75.8 

72 

68.7 

STEAM 


339 


FLUE    AREA   REQUIRED   FOR   THE   PASSAGE   OF   A   GIVEN   VOLUME   OF 
AIR    AT    A    GIVEN    VELOCITY—  (Continued). 


Volume  in 

Velocity  in  Feet  per  Minute. 

Cubic  I1  eet 
per  Minute. 

2200 

2300 

2400 

2600 

2700 

2800 

2900 

3000 

3100 

100 

6.6 

6.3 

6 

5.5 

5.3 

5.1 

5 

4.8 

4.6 

125 

8.2 

7.8 

7.5 

6.9 

6.7 

6.4 

6.2 

6 

5.8 

150 

9.8 

9.4 

9 

8 

8 

7.7 

7.5 

7.2 

7 

175 

11.5 

11 

10.5 

9.7 

9.3 

9 

8.7 

8.4 

8.1 

200 

13.1 

12.5 

12 

11.1 

10.7 

10.3 

9.9 

9.6 

9.3 

225 

14.7 

14.1 

13.5 

12.5 

12 

11.6 

11.2 

10.8 

10.4 

250 

16.4 

15.7 

15 

13.9 

13.3 

12.9 

12.4 

12, 

11.6 

275 

18 

17.2 

16.5 

15.2 

14.7 

14.1 

13.7 

13.2 

12.8 

300 

19.6 

18.8 

18 

16.6 

16 

15.4 

14.9 

14.4 

13.9 

325 

21.3 

20.6 

19.5 

18 

17.3 

16.7 

16.1 

15.6 

15.1 

350 

22.9 

21.9 

21 

19.4 

18.7 

18 

17.4 

16.8 

16.3 

375 

24.5 

23.5 

22.5 

20.8 

20 

19.3 

18.6 

18 

17.4 

400 

26.2 

25 

24 

22.2 

21.3 

20.6 

19.8 

19.2 

18.6 

425 

27.8 

26.6 

25.5 

23.5 

22.7 

21.9 

21.1 

20.4 

19.7 

450 

29.5 

28.2 

27 

24.9 

24 

23.1 

22.3 

21.6 

20.9 

475 

31.1 

29.7 

28.5 

26.3 

25.3 

24.4 

23.6 

22.8 

22.1 

500 

32.7 

31.3 

30 

27.7 

26.7 

25.7 

24.8 

24 

23.2 

525 

34.4 

32.9 

31.5 

29.1 

28 

26.9 

25 

25.2 

24.4 

550 

36 

34.4 

33 

30.5 

29.3 

28.3 

27.3 

26.4 

25.5 

575 

37.6 

36 

34.5 

31.9 

30.7 

29.6 

28.5 

27.6 

26.7 

600 

39.3 

37.6 

36 

33.2 

32 

30.8 

29.8 

28.8 

27.8 

625 

40.9 

39.1 

37.5 

34.6 

33.3 

32.1 

31 

30 

29 

650 

42.5 

40.7 

39 

36 

34.7 

33.4 

32.2 

31.2 

30.2 

675 

44.1 

42.3 

40.5 

37.5 

36 

34.7 

33.5 

32.4 

31.3 

700 

45.8 

43.8 

42 

38.8 

37.3 

36 

34.7 

33.6 

32.5 

725 

47.4 

45.4 

43.5 

40.2 

38.7 

37.3 

36 

34.8 

33.6 

750 

49.1 

47 

45 

41.5 

40 

38.6 

37.2 

36 

34.8 

775 

50.7 

48.5 

46.5 

42.9 

41.3 

39.9 

38.5 

37.2 

36 

800 

52.4 

50.1 

48 

44.3 

42.7 

41.2 

39.7 

38.4 

37.1 

825 

54 

51.7 

49.5 

45.7 

44 

42.4 

40.9 

39.6 

38.3 

850 

55.6 

53.2 

51 

47.1 

45.3 

43.7 

42.2 

40.8 

39.4 

875 

57.3 

54.8 

52.5 

48.5 

46.7 

45 

43.4 

42 

40.6 

900 

58.9 

56.3 

54 

49.9 

48 

46.3 

44.6 

43.2 

41.8 

925 

60.5 

57.9 

55.5 

51.3 

49.3 

47.6 

46 

44.4 

42.9 

950 

62.2 

59.5 

57 

52.6 

50.7 

48.8 

47.1 

45.6 

44.1 

975 

63.8 

61.0 

58.5 

54 

52 

50.2 

48.4 

46.8 

45.3 

1000 

66 

62.6 

60 

55.4 

53.3 

51.4 

49.6 

48 

46.4 

340  AMERICAN   GAS-ENGINEERING  PRACTICE. 


PERCENTAGE  OP  THE  TOTAL  HEAT  VALUE  OF  THE  COAL  REPRESENTED 

BY  THE  VARYING  AMOUNTS  OF  CO2  IN  FLUE-GAS.* 

* 

CO9,  Heat  Value  of  Coal, 

Per  Cent.  Per  Cent. 

2 5.3 

3 8.0 

4 10.8 

5 13.7 

6 16.6 

7 19.6 

8 23.0 

9 26.5 

10..  .30.0 


*  From  H.  H.  Campbell's  work  on  the  Manufacture  of  Iron  and  Steel, 
page  243. 


CHAPTER  XXI. 
MATHEMATICAL  TABLES. 

DIMENSIONS   OF  CIRCLES,    POWERS,    AND   ROOTS. 


Number  or 
Diameter. 

Circum- 
ference. 

Circular 
Area. 

Square. 

Cube. 

Square 
Root. 

Cube  Root. 

1 

3.1416 

0.7854 

1 

1 

1.000 

1.000 

2 

6.2832 

3.1416 

4 

8 

1.414 

1.259 

3 

9.4248 

7.0686 

9 

27 

1.732 

1.442 

4 

12.57 

12.57 

16 

64 

2.000 

1.587 

5 

15.71 

19.63 

25 

125 

2.236 

1.709 

6 

18.85 

28.27 

36 

216 

2.449 

1.817 

7 

21.99 

38.48 

49 

343 

2.645 

1.912 

8 

25.13 

50.27 

64 

512 

2.828 

2.000 

9 

28.27 

63.62 

81 

729 

3.000 

2.080 

10 

31.42 

78.54 

100 

1000 

3.162 

2.154 

11 

34.56 

95.03 

121 

1331 

3.316 

2.223 

12 

37.70 

113.10 

144 

1728 

3.464 

2.289 

13 

40.84 

132.73 

169 

2197 

3.605 

2.351 

14 

43.98 

153.94 

196 

2744 

3.741 

2.410 

15 

47.12 

176.71 

225 

3375 

3.872 

2.466 

16 

50.26 

201.06 

256 

4096 

4.000 

2.519 

17 

53.41 

226.98 

289 

4913 

4.123 

2.571 

18 

56.55 

254.47 

324 

5832 

4.242 

2.620 

19 

59.69 

283.53 

361 

6859 

4.358 

2.668 

20 

62.83 

314.16 

400 

8000 

4.472 

2.714 

21 

65.97 

346.36 

441 

9261 

4.582 

2.758 

22 

69.11 

380.13 

484 

10648 

4.690 

2.802 

23 

72.26 

415.48 

529 

12167 

4.795 

2.843 

24 

75.40 

452.39 

576 

13824 

4.898 

2.884 

25 

78.54 

490.87 

625 

15625 

5.000 

2.924 

26 

81.68 

530.93 

676 

17576 

5.099 

2.962 

27 

84.82 

572.56 

729 

19683 

5.196 

3.000 

28 

87.96 

615.75 

784 

21952 

5.291 

3.036 

29 

91.11 

660.52 

841 

24389 

5.385 

3.072 

30 

94.25 

706.86 

900 

27000 

5.477 

3.107 

31 

97.39 

754.77 

961 

29791 

5.567 

3.141 

32 

100.53 

804.25 

1024 

32768 

5.656 

3.174 

33 

103.67 

855.30 

1089 

35937 

5.744 

3.207 

341 


342  AMERICAN  GAS-ENGINEERING  PRACTICE. 

DIMENSIONS   OF   CIRCLES,    POWERS,    AND    ROOTS—  (Continued). 


Number  or 
Diameter. 

Circum- 
ference. 

Circular 
Area. 

Square. 

Cube. 

Square 
Root. 

Cube  Root. 

34 

106.81 

907.92 

1156 

39304 

5.830 

3.239 

35 

109.96 

962.11 

1225 

42875 

5.916 

3.271 

36 

113.10 

1017.88 

1296 

46656 

6.000 

3.301 

a? 

116.24 

1075.21 

1369 

50653 

6.082 

3.332 

38 

119.38 

1134.11 

1444 

54872 

6.164 

3.361 

39 

122.52 

1194.59 

1521 

59319 

6.244 

3.391 

40 

125.66 

1256.64 

1600 

64000 

6.326 

3.419 

42 

131.95 

1385.44 

1764 

74088 

6.480 

3.476 

44 

138.23 

1520.53 

1936 

85184 

6.633 

3.530 

46 

144.51 

1661.90 

2116 

97336 

6.782 

3.583 

48 

150.80 

1809.56 

2304 

110592 

6.928 

3.634 

50 

157.08  ' 

1963.50 

2500 

125000 

7.071 

3.684 

52 

163.36 

2123.72 

2704 

140608 

7.211 

3.732 

54 

169.65 

2290.22 

2916 

157464 

7.348 

3.779 

56 

175.93 

2463.01 

3136 

175616 

7.483 

3.825 

58 

182.21 

2642.08 

3364 

195112 

7.615 

3.870 

60 

188.50 

2827.43 

3600 

216000 

7.745 

3.914 

62 

194.78 

3019.07 

3844 

238328 

7.874 

3.957 

64 

201.06 

3216.99 

4096 

262144 

8.000 

4.000 

66 

207.34 

3421  .  19 

4356 

287496 

8.124 

4.041 

68 

213.63 

3631.68 

4624 

314432 

8.246 

4.081 

70 

219.91 

3848.45 

4900 

343000 

8.366 

4.121 

72 

226.19 

4071.50 

5184 

373248 

8.485 

4.160 

74 

232.48 

4300.84 

5476 

405224 

8.602 

4.198 

76 

238.76 

4536.46 

5776 

438976 

8.717 

4.235 

78 

245.04 

4778.36 

6084 

474552 

8.831 

4.272 

80 

251.33 

5026.55 

6400 

512000 

8.944 

4.308 

82 

257.61 

5281.02 

6724 

551368 

9.055 

4.344 

84 

263.89 

5541.77 

7056 

592704 

9.165 

4.379 

86 

270.18 

5808.80 

7396 

636056 

9.273 

4.414 

88 

276.46 

6082.12 

7744 

681472 

9.380 

4.447 

90 

282.74 

6361.73 

8100 

729000 

9.486 

4.481 

92 

289.03 

6647.61 

8464 

778688 

9.591 

4.514 

94 

295.31 

6939.78 

8836 

830584 

9.695 

4.546 

96 

301.59 

7238.23 

9216 

884736 

9.797 

4.578 

98 

307.88 

7542.96 

9604 

941192 

9.899 

4.610 

100 

314.16 

7853.98 

10000 

1000000 

10.000 

4.641 

102 

320.41 

8171.28 

10404 

1061208 

10.099 

4.672 

104 

326.73 

8494.87 

10816 

1124864 

10.198 

4.702 

106 

333.01 

8824.73 

11236 

1191016 

10.295 

4.732 

108 

339.29 

9160.88 

11664 

1259712 

10.392 

4.762 

11« 

345.57 

9503.32 

12100 

1331000 

10.488 

4.791 

112 

351.86 

9852.03 

12544 

1404928 

10.583 

4.820 

114 

358.14 

10207.03 

12996 

1481544 

10.677 

4.848 

116 

364.42 

10568.32 

13456 

1560896 

10.770 

4.876 

118 

370.71 

10935.88 

13924 

1643032 

10.862 

4.904 

120 

376.99 

11309.73 

14400 

1728000 

10.954 

4.932 

122 

383.27 

11689.87 

14884 

1815848 

11.045 

4.959 

MATHEMATICAL  TABLES. 


343 


TABLE   OF  DIAMETERS,  CIRCUMFERENCES,  AND  AREAS  OF  CIRCLES,  AND 
SIDES   OF  EQUAL  SQUARES. 


Diam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 
Square. 

Diam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 
Square. 

11 

34.557 

95.033 

9.7482 

1 

0.7854 

0.0490 

0.2215 

Hi 

35.343 

99.402 

9.9698 

1.5708 

.1963 

.4431 

Hi 

36.128 

103.869 

10.191 

£ 

2.3562 

.4417 

.6646 

111 

36.913 

108.434 

10.413 

1 

3.1416 

.7854 

.8862 

12 

37.699 

113.097 

10.634 

1} 

3.9270 

1.2271 

1  .  1077 

121 

38.484 

117.859 

10.856 

1} 

4.7124 

1.7671 

1.3293 

12£ 

39.270 

122.718 

11.077 

If 

5.4978 

2.4052 

1.5508 

12| 

40.055 

127.676 

11.299 

2 

6.2832 

3.1416 

1.7724 

13 

40.840 

132.732 

11.520 

2* 

7.0686 

3.9760 

J.9939 

131 

41.626 

137.886 

11.742 

2* 

7.8540 

4.9087 

2.2155 

13J 

42.411 

143.139 

11.963 

2J 

8.6394 

5.9395 

2.4370 

13| 

43.197 

148.489 

12.185 

3" 

9.4248 

7.0686 

2.6586 

14 

43.982 

153.938 

12.406 

31 

10.210 

8.2957 

2.8801 

141 

44.767 

159.485 

12.628 

3* 

10.995 

9.6211 

3.1017 

14| 

45.553 

165.130 

12.850 

3| 

11.781 

11.044 

3.3232 

14| 

46.338 

170.873 

13.071 

4 

12.566 

12.566 

3.5448 

15 

47.124 

176.715 

13.293 

41 

13.351 

14.186 

3.7663 

151 

47.909 

182.654 

13.514 

4i 

14.137 

15.904 

3.9880 

15£ 

48.694 

188.692 

13.736 

4| 

14.922 

17.720 

4.2095 

15| 

49.480 

194.828 

13.957 

5 

15.708 

19.635 

4.4310 

16 

50.265 

201.062 

14.174 

51 

16.493 

21.647 

4.6525 

161 

51.051 

207.394 

14.400 

5i 

17.278 

23.758 

4.8741 

16i 

51.836 

213.825 

14.622 

5| 

18.064 

25.967 

5.0956 

16| 

52.621 

220.353 

14.843 

6 

18.849 

28.274 

5.3172 

17 

53.407 

226.980 

15.065 

61 

19.635 

30.697 

5.5388 

171 

54.192 

233.705 

15.286 

6i 

20.420 

33.183 

5.7603 

17£ 

54.978 

240.528 

15.508 

6| 

21.205 

35.784 

5.9819 

17f 

55.763 

247.450 

15.730 

7 

21.991 

38.484 

6.2034 

18 

56.548' 

254.469 

15.951 

71 

22.776 

41.282 

6.4350 

181 

57.334 

261.587 

16.173 

7i 

23.562 

44.178 

6.6465 

18i 

58.119 

268.803 

16.394 

7| 

24.347 

47.173 

6.8681 

18| 

58.905 

276.117 

16.616 

8 

25.132 

50.265 

7.0897 

19 

59.690 

283.529 

16.837 

81 

25.918 

53.456 

7.3112 

191 

60.475 

291.039 

17.060 

8i 

26.703 

56.745 

7.5328 

19^ 

61.261 

298.648 

17.280 

81 

27.489 

60.132 

7.7544 

19| 

62.046 

305.355 

17.502 

9 

28.274 

63.617 

7.9760 

20 

62.832 

314.160 

17.724 

91 

29.059 

67.200 

8.1974 

201 

63.617 

322.063 

17.945 

9i 

29.845 

70.882 

8.4190 

20J 

64.402 

330.064 

18.167 

9| 

30.630 

74.662 

8.6405 

20| 

65.188 

338.163 

18.388 

10 

31.416 

78.540 

8.8620 

21 

65.973 

346.361 

18.610 

101 

32.201 

82.516 

9.0836 

211 

66.759 

354.657 

18.831 

10i 

32.986 

86.590 

9.3051 

2l| 

67.544 

363.051 

19.053 

10| 

33.772 

90.762 

9.5267 

2l| 

68.329 

371.543 

19.274 

344 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE   OF  DIAMETERS,  CIRCUMFERENCES,  AND   AREAS  OF  CIRCLES,  AND 
SIDES   OF   EQUAL   SQUARES— (Confined). 


Diam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 
Square. 

Diam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 
Square. 

22 

69.115 

380.133 

19.496 

33 

103.672 

855.300 

29.244 

221 

69.900 

388.822 

19.718 

331 

104.458 

868.308 

29.466 

22* 

70.686 

397.608 

19.939 

33* 

105.243 

881.415 

29.687 

22! 

71.471 

406.493 

20.161 

33§ 

106.029 

894.619 

29.909 

23 

72.256 

415.476 

20.382 

34 

106.814 

907.922 

30.131 

231 

73.042 

424.557 

20.604 

341 

107.599 

921.323 

30.352 

23* 

73.827 

433.731 

20.825 

34* 

108.385 

934.822 

30.574 

23! 

74.613 

443.014 

21.047 

34! 

109.170 

948.419 

30.795 

24 

75.398 

452.390 

21.268 

35 

109.956 

962.115 

31.017 

241 

76.183 

461.864 

21.490 

35J 

110.741 

975.908 

31.238 

24* 

76.969 

471.436 

21.712 

35* 

111.526 

989.800 

31.460 

24§ 

77.754 

481  .  106 

21.933 

35! 

112.312 

1003.79 

31.681 

25 

78.540 

490.875 

22.155 

36 

113.097 

1017.87 

31.903 

251 

79.325 

500.741 

22.376 

36J 

113.883 

1032.06 

32.124 

25* 

80.110 

510.706 

22.598 

36* 

114.668 

1046.39 

32.349 

25| 

80.896 

520.769 

22.819 

36! 

115.453 

1060.73 

32.567 

26 

81.681 

530.930 

23.041 

37 

116.239 

1075.21 

32.789 

261 

82.467 

541  .  189 

23.262 

371 

117.024 

1089.79 

33.011 

26* 

83.252 

551.547 

23.484 

37* 

117.810 

1104.46 

33.232 

26! 

84.037 

562.002 

23.708 

37! 

118.595 

1119.24 

33.454 

27 

84.823 

672.556 

23.927 

38 

119.380 

1134.11 

33.675 

271 

85.608 

583.208 

24.149 

381 

120.166 

1149.08 

33.897 

27* 

86.394 

593.958 

24.370 

38* 

120.951 

1164.15 

34.118 

27| 

87.179 

604.807 

24.592 

38! 

121.737 

1179.32 

34.340 

28 

87.964 

615.763 

24.813 

39 

122.522 

1194.59 

34.561 

281 

88.750 

626.798 

25.035 

391 

123.307 

1209.95 

34.783 

28* 

89.535 

637.941 

25.256 

39* 

124.093 

1225.42 

35.005 

28| 

90.321 

649.182 

25.478 

39! 

124.878 

1240.98 

35.226 

29 

91.106 

660.521 

25.699 

40 

125.664 

1256.64 

35.448 

291 

91.891 

671.958 

25.921 

401 

126.449 

1272.39 

35.669 

29* 

92.677 

683.494 

26.143 

40* 

127.234 

1288.25 

35.891 

29! 

93.462 

695.128 

26.364 

40f 

128.020 

1304.20 

36.112 

30 

94.248 

706.860 

26.586 

41 

128.805 

1320.25 

36.334 

301 

95.033 

718.690 

26.807 

411 

129.591 

1336.40 

36.555 

30* 

95.818 

730.618 

27.029 

41* 

130.376 

1352.65 

36.777 

30! 

96.604 

742.644 

27.250 

41! 

131.161 

1369.00 

36.999 

31 

97.389 

754.769 

27.472 

42 

131.947 

1385.44 

37.220 

311 

98.175 

766.992 

27.693 

421 

132.732 

1401.98 

37.442 

31* 

98.968 

779.313 

27.915 

42* 

133.518 

1418.62 

37.663 

31| 

99.745 

791.732 

28.136 

42! 

134.303 

1435.36 

37.885 

32 

100.531 

804.249 

28.358 

43 

135.088 

1452.20 

38.106 

321 

101.316 

816.865 

28.580 

431 

135.874 

1469.13 

38.328 

32* 

102.102 

829.578 

28.801 

43* 

136.659 

1486.17 

38.549 

32| 

102.887 

842.390 

29.023 

43! 

137.445 

1503.30 

38.771 

MATHEMATICAL  TABLES. 


345 


TABLE  OF  DIAMETERS,  CIRCUMFERENCES,  AND  AREAS  OF  CIRCLES,  AND 
SIDES   OF    EQUAL  SQUARES—  (Continued). 


Diam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 
Square. 

Diam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 
Square. 

44 

138.230 

1520.53 

38.993 

55 

172.788 

2375.83 

48.741 

441 

139.015 

1537.86 

39.214 

55i 

173.573 

2397.48 

48.962 

44  $ 

139.801 

1555.28 

39.436 

55£ 

174.358 

2419.22 

49.184 

44! 

140.586 

1572.81 

39.657 

55! 

175.144 

2441.07 

49.405 

45 

141.372 

1590.43 

39.879 

56 

175.929 

2463.01 

49.627 

451 

142.157 

1608.15 

40.110 

561 

176.715 

2485.05 

49.848 

45* 

142.942 

1625.97 

40.322 

56  J 

177.500 

2507.19 

50.070 

45| 

143.728 

1643.89 

40.543 

56| 

178.285 

2529.42 

50.291 

46 

144.513 

1661.90 

40.765 

57 

179.071 

2551.76 

50.513 

46i 

145.299 

1680.01 

40.986 

571 

179.856 

2574.19 

50.735 

46J 

146.084 

1698.23 

41.208 

57^ 

180.642 

2596.72 

50.956 

46| 

146.869 

1716.54 

41.429 

57| 

181.427 

2619.35 

51.178 

47 

147.655 

1734.94 

41.651 

58 

182.212 

2642.08 

51.399 

471 

148.440 

1753.45 

41.873 

581 

182.998 

2664.91 

51.621 

47i 

149.226 

1772.05 

42.094 

58£ 

1^3.783 

2687.83 

51.842 

47| 

150.011 

1790.76 

42.316 

58| 

184.569 

2710.85 

52.064 

48 

150.796 

1809.56 

42.537 

59 

185.354 

2733.97 

52.285 

481 

151.582 

1828.46 

42.759 

591 

186.139 

2757.19 

52.507 

48J 

152.367 

1847.45 

42.980 

59  *, 

186.925 

2780.51 

52.725 

48  1 

153.153 

1866.55 

43.202 

59! 

187.710 

2803.92 

52.950 

49 

153.938 

1885.74 

43.423 

60 

188.496 

2827.44 

53.172 

491 

154.723 

1905.03 

43.645 

601 

189.281 

2851.45 

53.393 

49i 

155.509 

1924.42 

43.867 

60| 

190.066 

2874.76 

53.615 

491 

156.294 

1943.91 

44.088 

60! 

190.852 

2898.56 

53.836 

50 

157.080 

1963.50 

44.310 

61 

191.637 

2922.47 

54.048 

501 

157.865 

1983.18 

44.531 

6U 

192.423 

2946.47 

54.279 

5Qi 

158.650 

2002.96 

44.753 

61J 

193.208 

2970.57 

54.501 

501 

159.436 

2022.84 

44.974 

6lf 

193.993 

2994.77 

54.723 

51 

160.221 

2042.82 

45  .  196 

62 

194.779 

3019.07 

54.944 

511 

161.207 

2062.90 

45.417 

62} 

195.564 

3043.47 

55.166 

51*. 

161.792 

2083.07 

45.639 

62*. 

196.350 

3067.96 

55.387 

51! 

162.577 

2103.34 

45.861 

62! 

197.135 

3092.56 

55.609 

52 

163.363 

2123.72 

46.082 

63 

197.920 

3117.25 

55.830 

521 

164.148 

2144.19 

46.304 

631 

198.706 

3142.04 

56.052 

524 

164.934 

2164.75 

46.525 

63* 

199.491 

3166.92 

56.273 

52f 

165.719 

2185.42 

46.747 

63| 

200.277 

3191.91 

56.495 

53 

166.504 

2206.18 

46.968 

64 

201.062 

3216.99 

56.716 

53| 

167.290 

2227.05 

47.190 

64} 

201.847 

3242.17 

56.931 

53J 

168.075 

2248.01 

47.411 

64* 

202.633 

3267.46 

57.159 

53| 

168.861 

2269.06 

47.633 

64| 

203.218 

3292.83 

57.381 

54 

169.646 

2290.22 

47.853 

65 

204.204 

3318.31 

57.603 

54i 

170.431 

2311.48 

48.076 

651 

204.989 

3343.88 

.57.824 

54£ 

171.217 

2332.83 

48.298 

65J 

205.774 

3369.56 

58.046 

54  1 

172.002 

2354.28 

48.519 

65! 

206.560 

3395.33 

58.267 

346 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE  OF  DIAMETERS,  CIRCUMFERENCES,  AND  AREAS  OF  CIRCLES,  AND 
SIDES    OF   EQUAL   SQUARES—  (Continued). 


Diani. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 
Square. 

Diam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 
Square. 

66 

207.345 

3421.20 

58.489 

77 

241.903 

4656.63 

68.237 

661 

208.131 

3447.16 

58.710 

771 

242.688 

4686.92 

68.459 

66* 

208.916 

3473.23 

58.932 

77* 

243.474 

4717.30 

68.680 

66! 

209.701 

3499.39 

59.154 

77| 

244.259 

4747.79 

68.902 

67 

210.487 

3525.66 

59.375 

78 

245.044 

4778.37 

69.123 

671 

211.272 

3552.01 

59.597 

781 

245.830 

4809.05 

69.345 

67* 

212.058 

3578.47 

59.818 

78* 

246.615 

4839.83 

69.566 

67| 

212.843 

3605.03 

60.040 

78! 

247.401 

4870.70 

69.788 

68 

213.628 

3631.68 

60.261 

79 

248.186 

4901.68 

70.009 

681 

214.414 

3658.44 

60.483 

791 

248.971 

4832.75 

70.231 

68* 

215.199 

3685.29 

60.704 

79* 

249.757 

4963.92 

70.453 

68| 

215.985 

3712.24 

60.926 

79| 

250.542 

4995.19 

70.674 

69 

216.770 

3739.28 

61.147 

80 

251.328 

5026.56 

70.869 

69J 

217.555 

3766.43 

61.369 

801 

252.113 

5058.01 

71.119 

69* 

218.341 

3793.67 

61.591 

£0* 

252.898 

5089.58 

71.339 

69| 

219.126 

3821.02 

61.812 

80! 

253.684 

5121.24 

71.562 

70 

219.912 

3848.46 

62.934 

81 

254.469 

5153.00 

71.782 

701 

220.697 

3875.99 

62.255 

811 

255.255 

5184.86 

72.005 

70* 

221.482 

3903.63 

62.477 

81* 

256.040 

5216.82 

72.225 

70| 

222.268 

3931.36 

62.698 

81! 

256.825 

5248.87 

72.449 

71 

223.053 

3959.20 

62.920 

82 

257.611 

5281.02 

72.668 

711 

223.839 

3987.13 

63.141 

821 

258.396 

5313.27 

72.892 

71* 

224.624 

4015.16 

63.363 

82* 

259.182 

5345.62 

73.111 

71| 

225.409 

4043.28 

63.545 

82| 

259.967 

5370.07 

73.335 

72 

226.195 

4071.51 

63.806 

83 

260.753 

5410.62 

73.554 

721 

226.980 

4099.83 

64.028 

831 

261.538 

5443.26 

73.778 

72* 

227.766 

4128.25 

64.249 

83* 

262.3*23 

5476.00 

73.997 

72| 

228.551 

4165.77 

64.471 

83| 

263.109 

5508.84 

74.221 

73 

229.336 

4185.39 

64.692 

84 

263.894 

5541.78 

74.440 

731 

230.122 

4212.11 

64.914 

841 

264.679 

5574.81 

74.664 

73* 

230.907 

4242.92 

65.135 

84* 

265.465 

5607.95 

74.884 

73! 

231.693 

4271.83 

65.357 

84! 

266.250 

5641.18 

75.107 

74 

232.478 

4300.85 

65.578 

85 

267.036 

5674.51 

75.327 

741 

233.263 

4329.95 

65.800 

851 

267.821 

5707.94 

75.550 

74* 

234.049 

4359.16 

66.022 

85* 

268.606 

5741.47 

75.770 

74! 

234.834 

4388.47 

66.243 

85! 

269.392 

5775.09 

75.994 

75 

235.620 

4417.87 

66.465 

86 

270.177 

5808.81 

76.213 

751 

236.405 

4447.37 

66.686 

861 

270.963 

5842.63 

76.437 

75* 

237  .  190 

4476.97 

66.908 

86* 

271.748 

5876.55 

76.656 

75| 

237.976 

4506.67 

67  .  129 

86f 

272.533 

5910.57 

76.880 

76 

238.761 

453«.47 

67.351 

87 

273.319 

5944.69 

77.099 

761 

239.547 

4566.36 

67.572 

871 

274.104 

5978.90 

77.323 

76* 

240.332 

4596.35 

67.794 

87* 

274.890 

6013.21 

77.542 

76| 

241.117 

4626.44 

68.016 

87! 

275.675 

6047.62 

77.766 

MATHEMATICAL  TABLES. 


347 


TABLE  OF  DIAMETERS,  CIRCUMFERENCES,  AND  AREAS  OF  CIRCLES,  AND 

SIDES    OF    EQUAL   SQUARES— (Continued). 


Diam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 
Square. 

Mam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 
Square. 

88 

276.460 

6018.13 

77.985 

99 

311.018 

7697.70 

87.736 

88} 

277.246 

6116.74 

78.209 

99j 

311.803 

7736.62 

87.958 

88| 

278.031 

6151.44 

78.428 

99? 

312.589 

7775.65 

88.179 

278.817 

6186.25 

78.652 

99| 

313.374 

7814.79 

88.401 

89 

279.602 

6221.15 

78.871 

100 

314.160 

7854.00 

88.622 

89} 

280.387 

6256.15 

79.095 

100] 

314.945 

7893.31 

88.844 

89* 

281.173 

6291.25 

79.315 

100* 

315.730 

7932.73 

89.065 

89| 

281.958 

6326.44 

79.538 

lOOf 

316.516 

7972.21 

89.287 

90 

282.744 

6361.74 

79.758 

101 

317.301 

8011.86 

89.508 

90} 

283.529 

6397  .  13 

79.982 

101} 

318.087 

8051.57 

89.730 

90i 

284.314 

6432.62 

80.201 

101* 

318.872 

8091.38 

89.952 

90f 

285.100 

6468.21 

80.424 

101| 

319.657 

8131.29 

90.173 

91 

285.885 

6503.89 

80.644 

102 

320.443 

8171.30 

90.395 

91} 

286.671 

6539.68 

80.868 

102} 

321.228 

8211.40 

90.616 

91£ 

287.456 

6573.56 

81.087 

102£ 

322.014 

8251.60 

90.838 

9l| 

288.241 

6611.54 

81.311 

102! 

322.799 

8291.86 

91.059 

92 

289.027 

6647.62 

81.530 

103 

323.584 

8332.30 

91.281 

92} 

289.812 

6683.80 

81.754 

103} 

324.370 

8372.80 

91.502 

92£ 

290.598 

6720.07 

81.973 

103* 

325.155 

8413.40 

91.724 

92J 

291.383 

6756.45 

82.197 

103| 

325.941 

8454.09 

91.946 

93 

292.168 

6792.92 

82.416 

104 

326.726 

8494.88 

92.167 

93} 

292.954 

6829.49 

82.640 

104} 

327.511 

8535.77 

92.389 

93£ 

293.739 

6866.16 

82.859 

104] 

328.297 

8576.76 

92.610 

93| 

294.535 

6902.92 

83.083 

1041 

329.082 

8617.85 

92.832 

94 

295.310 

6939.79 

83.302 

105 

329.868 

8569.03 

93.053 

94} 

296.095 

6976.75 

83.526 

105} 

330.653 

8700.31 

93.275 

94£ 

296.881 

7013.81 

83.746 

105i 

331.438 

8741.69 

93.496 

94| 

297.666 

7050.97 

83.970 

105! 

332.224 

8783.17 

93.718 

95 

298.452 

7088.23 

84.189 

106 

333.009 

8824.75 

93.940 

95} 

299.237 

7125.58 

84.413 

106} 

333.794 

8866.42 

94.161 

95i 

300.022 

7163.04 

84.632 

1C6J 

334.580 

8908.20 

94.383 

95| 

300.808 

7200.59 

84.856 

106s 

335.365 

8950.07 

94.604 

96 

301.593 

7238.24 

85.077 

107 

306.151 

8992.04 

94.826 

96} 

302.379 

7275.99 

85.299 

107} 

306.935 

9034.11 

95.047 

96£ 

303.164 

7313.84 

85.520 

107^ 

337.722 

9076.27 

95.269 

96f 

303.949 

7351.78 

85.742 

107J 

338.506 

9118.54 

95.491 

97 

304.735 

7389.82 

85.964 

108 

339.292 

9160.90 

95.712 

97} 

305.520 

7427.96 

86.185 

108} 

340.077 

9203.36 

95.534 

97i 

306.306 

7466.20 

86.407 

108. 

340.863 

9245.92 

96.155 

97| 

307.091 

7504.54 

86.628 

108? 

341.648 

9288.58 

96.377 

98 

307.876 

7542.98 

86.850 

109 

342.434 

9331.33 

96.598 

98} 

308.662 

7581.51 

87.071 

109} 

343.219 

9374.18 

96.820 

98i 

309.447 

7620.14 

87.293 

109i 

344.005 

9417.14 

97.041 

98| 

310.233 

7658.87 

87.514 

109: 

344.789 

9460.19 

97.263 

348 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE  OF  DIAMETERS,  CIRCUMFERENCES,  AND  AREAS  OF  CIRCLES,  AND 
SIDES    OF   EQUAL    SQUARES— (Confined). 


Diam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 
Square. 

Diam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 
Square. 

110 

345.575 

9503.34 

97.485 

121 

380.132 

11499.04 

107.334 

1101 

346.360 

9546.59 

97.707 

1211 

380.918 

11546.61 

107.455 

110$ 

347.146 

9589.93 

97.928 

121* 

381.703 

11594.27 

107.677 

110| 

347.931 

9633.37 

98.150 

121! 

382.489 

11642.0c 

107.898 

Ill 

348.716 

9776.91 

98.371 

122 

383.274 

11689.  8S 

108.120 

11U 

349.502 

9720.55 

98.593 

122-1 

384.059 

11747.85 

108.341 

111* 

350.287 

9764.29 

98.814 

122$ 

384.845 

11785.91 

108.563 

111| 

351.073 

9808.12 

99.036 

122f 

385.630 

11834.0t 

108.784 

112 

351.858 

9852.06 

99.258 

123 

386.416 

11882.31 

109.006 

1121 

352.643 

9896.09 

99.479 

123-1 

387.201 

11930.67 

109.228 

112* 

353.429 

9940.21 

99.701 

123$ 

387.986 

11979.11 

109.449 

112! 

354.214 

9984.45 

99.922 

123! 

388.772 

12027.6e 

109.671 

113 

355.000 

10028.77 

100.144 

124 

389.557 

12076.31 

109.892 

1131 

355.785 

10073.20 

100.365 

124} 

390.343 

12  125.  Of 

110.114 

113* 

356.570 

10117.72 

100.587 

124* 

391.128 

12173.  9C 

110.335 

113| 

357.356 

10162.34 

100.808 

124! 

391.913 

12222.  8< 

110.557 

114 

358.141 

10207.06 

101.030 

125 

392.699 

12271.  8£ 

110.778 

114$ 

358.927 

10251.88 

101.252 

1251 

393.484 

12321.01 

111.000 

114* 

359.712 

10296.79 

101.473 

125$ 

394.270 

12370.25 

111.222 

114f 

360.497 

10341.80 

101.695 

125f 

395.055 

12419.5* 

111.443 

115 

361.283 

10386.92 

101.916 

126 

395.840 

12469.01 

111.665 

1151 

362.068 

10432.12 

102.138 

1261 

396.626 

12518.54 

111.886 

115* 

362.854 

10477.43 

102.359 

126* 

397.411 

12568.17 

112.108 

115| 

363.639 

10522.  8< 

102.581 

126! 

398.197 

12617.  8£ 

112.329 

116 

364.424 

10568.  3< 

102.802 

127 

398.982 

12667.72 

112.551 

1161 

365.210 

10613.94 

103.024 

1271 

399.767 

12717.64 

112.772 

116* 

365.995 

10659.65 

103.246 

127$ 

400.553 

12767.66 

112.994 

116| 

366.780 

10705.44 

103.467 

127! 

401.338 

12817.  7£ 

113.216 

117 

367.566 

10751.34 

103.689 

128 

402.124 

12868.  Of 

113.437 

1171 

368.351 

10797.34 

103.910 

1281 

402.909 

12918.3] 

113.659 

117* 

389.137 

10843.43 

104.132 

128$ 

403.694 

12968.71 

113.880 

117| 

369.922 

10889.62 

104.353 

128! 

404.480 

13019.22 

114.102 

118 

370.708 

10935.91 

104.575 

129 

405.265 

13069.84 

114.323 

1181 

371.493 

10982.30 

104.796 

1291 

406.051 

13120.55 

114.545 

118* 

371.278 

11028.78 

105.018 

129* 

406.836 

13171.35 

114.767 

118| 

371.064 

11075.37 

105.240 

129! 

407.621 

13222.26 

114.988 

119 

373.849 

11122.05 

105.461 

130 

408.407 

13273.26 

115.210 

1191 

374.635 

11168.83 

105.683 

1301 

409.192 

13324.36 

115.431 

119* 

375.420 

11215.71 

105.904 

130* 

409.977 

13375.56 

115.653 

119! 

376.205 

11262.69 

106.126 

130! 

410.763 

13426.85 

115.874 

120 

376.991 

11309.76 

106.347 

131 

411.548 

13478.25 

116.096 

1201 

377.776 

11356.93 

106.569 

1311 

412.334 

13529.7^ 

116.317 

120* 

378.562 

11404.20 

106  .  790 

131* 

413.119 

13581.33 

116.539 

120| 

379.347 

11451.57 

107.012 

131! 

413.904 

13633.01 

116.761 

MATHEMATICAL  TABLES. 


349 


TABLE  OF  DIAMETERS,  CIRCUMFERENCES,  AND  AREAS  OF  CIRCLES,  AND 
SIDES   OF   EQUAL   SQUARES—  (Continued).    • 


Diam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 
Square. 

)iam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 
Square. 

132 

414.690 

13684.81 

116.982 

143 

449.247 

16060.64 

126.731 

1321 

415.475 

13736.70 

117.204 

1431 

450.033 

16116.85 

126.952 

132* 

416.260 

13788.68 

117.425 

1431 

450.818 

16173.15 

127.174 

132| 

417.046 

13840.76 

117.647 

143| 

451.604 

16229.55 

127.395 

133 

417.831 

13892.94 

117.868 

144 

452.389 

16286.05 

127.617 

1331 

418.617 

13945.22 

118.090 

1441 

453  .  174 

16334.66 

127.838 

133* 

419.402 

13997.60 

118.311 

144f 

453.960 

16399.35 

128.060 

133| 

420.188 

14050.07 

118.533 

144| 

454.745 

16456.14 

128.281 

134 

420.973 

14102.64 

118.755 

145 

455.531 

16513.04 

128.503 

1341 

421.758 

14155.31 

118.976 

1451 

456.316 

16570.03 

128.725 

1341 

422.544 

14208.08 

119.198 

145* 

457.101 

16627.11 

128.946 

134f 

423.329 

14260.95 

119.419 

145| 

457.887 

16684.30 

129.168 

135 

424.115 

14313.92 

119.641 

146 

458.672 

16741.59 

129.389 

1351 

424.900 

14366.98 

119.862 

1461 

459.458 

16798.97 

129.611 

1351 

425.685 

14420.14 

120.084 

146} 

460.243 

16856.45 

129.832 

135| 

426.470 

14473.40 

120.305 

146| 

461.028 

16914.03 

130.054 

136 

427.256 

14526.76 

120.527 

147 

461.814 

16971.71 

130.276 

1361 

428.042 

14580.21 

120.749 

1471 

462.599 

17029.48 

130.497 

1361 

428.827 

14633.77 

120.970 

1471 

463.385 

17087.36 

130.719 

133| 

429.612 

14687.42 

121.192 

147| 

464.170 

17145.33 

130.940 

137 

430.398 

14741.12 

121.413 

148 

464.955 

17203.40 

131.162 

1371 

431.183 

14795.02 

121.635 

1481 

465.741 

17261.57 

131.383 

1371 

431.969 

14848.97 

121.856 

1481 

466.526 

17319.84 

131.605 

137| 

432.554 

14903.01 

122.078 

148| 

467.312 

17378.20 

131.826 

138 

433.539 

14957.16 

122.299 

149 

468.097 

17436.67 

132.048 

1381 

434.325 

15011.40 

122.521 

1491 

468.882 

17495.22 

132.270 

138J 

435.110 

15065.74 

122.743 

1491 

469.668 

17553.89 

132.491 

13SJ 

435.896 

15120.18 

122.964 

149| 

470.453 

17612.64 

132.713 

139 

436.681 

15174.71 

123.186 

150 

471.239 

17671.50 

132.934 

1391 

437.466 

15229.35 

123.407 

1501 

472.024 

17730.45 

133.156 

1391 

438.252 

15284.08 

123.629 

1501 

472.809 

17789.51 

133.377 

1391 

439.037 

15338.91 

123.850 

150| 

473.595 

17848.66 

133.599 

140 

439.823 

15393.84 

124.072 

151 

474.380 

17907.91 

133.820 

140J 

440.608 

15448.87 

124.293 

1511 

475.165 

17967.2,r 

134.042 

140* 

441.393 

15503.99 

124.515 

1511 

475.951 

18026.7C 

134.264 

140f 

442.179 

15559.22 

124.737 

151| 

476.736 

18086.24 

134.485 

141 

442.964 

15614.54 

124.958 

152 

477.522 

18145.88 

134.707 

1411 

443.750 

15669.96 

125.180 

1521 

478.307 

18205.62 

134.928 

14ll 

444.535 

15725.48 

125.401 

1521 

479.092 

18265.46 

135.150 

141| 

445.320 

15781.09 

125.623 

152| 

479.878 

18325.  3e 

135.371 

142 

446.106 

15836.81 

125.844 

153 

480.663 

18385.43 

135.593 

1421 

446.891 

15892.62 

126.066 

1531 

481.449 

18445.56 

135.814 

142* 

447.677 

15948.53 

126.287 

1531 

482.234 

18505.79 

T36.036 

142| 

448.462 

16004.54 

126.509 

153| 

483.019 

18566.12 

136.258 

350 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE  OF  DIAMETERS,  CIRCUMFERENCES,  AND  AREAS  OF  CIRCLES,  AND 
SIDES  OF  EQUAL  SQUARES— (Continued). 


Diam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 
Square. 

Diam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 
Square. 

154 

483.805 

18626.55 

136.479 

165 

518.362 

21382.52 

146.228 

154* 

484.590 

18687.07 

136.701 

165} 

519.148 

21447.36 

146.449 

154* 

485.376 

18747.69 

136.922 

65* 

519.933 

21512.30 

146.671 

154f 

486.161 

18808.42 

137.144 

165| 

520.719 

21577.34 

146.892 

155 

486.946 

18869.24 

137.365 

166 

521.504 

21642.48 

147.114 

1551 

487.932 

18930.15 

137.587 

166} 

522.290 

21707.72 

147.335 

155* 

488.517 

18991  .  17 

137.808 

166* 

523.075 

21773.06 

147.557 

155| 

489.303 

19052.28 

138.030 

66| 

523.860 

21838.49 

147.779 

156 

490.088 

19113.49 

138.252 

167 

524.646 

21904.02 

148.000 

1561 

490.873 

19174.80 

138.473 

167} 

525.431 

21969.65 

148.222 

156* 

491.659 

19236.21 

138.695 

167* 

526.216 

22035.08 

148.443 

156f 

492.444 

19297.72 

138.916 

167| 

527.002 

22101.21 

148.665 

157 

493.230 

19359.32 

139.138 

168 

527.787 

22167.13 

148.886 

1571 

494.015 

19421.03 

139.359 

168} 

528.573 

22233.15 

149.108 

157* 

494.800 

19482.83 

139.581 

168* 

529.358 

22299  .  27 

149.329 

157J 

495.586 

19544.73 

139.802 

168| 

530.143 

22365.49 

149.551 

158 

496.371 

19605.73 

140.024 

169 

530.929 

22431.81 

149.773 

1581 

497.157 

19668.82 

140.246 

169} 

531.714 

22498.22 

149.994 

158* 

497.942 

19731.02 

140.467 

169* 

532.500 

22564.74 

150.216 

158| 

498.727 

19793.31 

140.689 

169| 

533.285 

22631.35 

150.437 

159 

499.513 

19855.70 

140.910 

170 

534.070 

22698.06 

150.659 

1591 

500.298 

19918.  IT 

141.132 

170} 

534.856 

22764.87 

150.880 

159* 

501.084 

19980.77 

141.353 

170* 

535.641 

22831.77 

151.102 

159| 

501.869 

20043.  4C 

141.575 

170| 

536.426 

22898.79 

151.323 

160 

502.654 

20106.24 

141.796 

171 

537.212 

22965.88 

151.545 

1601 

503.440 

20169.12 

142.018 

171} 

537.997 

23033.08 

151.767 

160* 

504.225 

20232.10 

142.240 

171* 

538.783 

23100.38 

151.988 

160| 

505.011 

20295.  If 

142.461 

17l| 

539.568 

23167.78 

152.210 

161 

505.796 

20358.35 

142.683 

172 

540.353 

23235.27 

152.431 

1611 

506.581 

20421.6? 

142.904 

172} 

541.139 

23302.87 

152.653 

161* 

507.367 

20485.00 

143  .  126 

172* 

541.924 

23370.56 

152.874 

161| 

508.152 

20548.47 

143.347 

172| 

542.710 

23438.35 

153.096 

162 

508.938 

20612.0;' 

143.569 

173 

543.495 

23506.24 

153.317 

162} 

509.723 

20675.70 

143.790 

173} 

544.280 

23574.22 

153  .  539 

162* 

510.508 

20739.47 

144.012 

173* 

545.066 

23642.31 

153.761 

162| 

511.294 

20803.33 

144.234 

173J 

545.851 

23710.49 

153.982 

163 

512.079 

20867.  2P 

144.455 

174 

546.637 

23778.77 

154.204 

1631 

512.865 

20931.35 

144.677 

174} 

547.422 

23847.15 

154.425 

163* 

513.650 

20995.51 

144.898 

174* 

548.207 

23915.63 

154.1647 

163| 

514.435 

21059.76 

145.120 

174| 

548.993 

23984.20 

154.868 

164 

515.221 

21124.12 

145.341 

175 

549.778 

24052.88 

155.090 

164} 

516.006 

21188.57 

145.563 

175} 

550.564 

24121.65 

155.311 

164* 

516.792 

21253.12 

145.784 

175* 

551.349 

24190.52 

155.533 

164f 

517.577 

21317.77 

146.006 

175| 

552.134 

24259.48 

155.755 

MATHEMATICAL   TABLES. 


351 


TABLE  OF  DIAMETERS,  CIRCUMFERENCES,  AND  AREAS  OF  CIRCLES,  AND 
SIDES  OF  EQUAL  SQUARES— (Continued'). 


Diam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 

Diam. 

Circum- 
ference. 

Area. 

Sides  of 
Equal 

Square. 

Square. 

176 

552.920 

24328.55 

155.976 

188 

590.619 

27759  .  18 

166.611 

1761 

553.705 

24397.71 

156.198 

1881 

591.404 

27833  .  05 

166.832 

1761 

554.491 

24466.98 

156.419 

1881 

592.190 

27907.03 

167.054 

176| 

555.276 

24536.34 

156.641 

188| 

592.975 

27981  .  10 

167.276 

177 

556.061 

24605.80 

156.862 

189 

593.761 

28055.27 

167.497 

1771 

556.847 

24675.35 

157.084 

1891 

594.546 

28129.54 

167.719 

177J 

557.632 

24745.01 

157.305 

1891 

595.331 

28203.91 

167.940 

177| 

558.418 

24814.76 

157.527 

189| 

596.117 

28278.38 

168.162 

178 

559.203 

24884.61 

157.749 

190 

596.902 

28352.94 

168.383 

1781 

559.988 

24954.56 

157.970 

1901 

597.687 

28427.60 

168.605 

1781 

560.774 

25024.61 

158.192 

190| 

598.473 

28502.36 

168.826 

178| 

561.559 

25094.76 

158.413 

190J 

599.258 

28577.22 

169.048 

179 

562.345 

25165.00 

158.635 

191 

600.044 

28652.18 

169.270 

1791 

563  .  130 

25235.34 

158.856 

1911 

600.829 

28727.23 

169.491 

1791 

563.915 

25305.78 

159.078 

1911 

601.614 

28802.39 

169.713 

179| 

564.701 

25376.32 

159.299 

19lf 

602.400 

28877.64 

169.934 

180 

565.486 

25446.96 

159.521 

192 

603  .  185 

28952.99 

170.156 

1801 

566.272 

25517.70 

159.743 

1921 

603.971 

29028.43 

170.377 

1801 

567.057 

25588.53 

159.964 

192* 

604.756 

29103.98 

170.599 

180| 

567.842 

25659.46 

160.186 

192| 

605.541 

29179.62 

170.820 

181 

568.628 

25730.49 

160.407 

193 

606.327 

29255.37 

171.042 

1811 

569.413 

25801.62 

160.629 

1931 

607.112 

29331.21 

171.264 

181* 

570.199 

25872.84 

160.850 

1931 

607.898 

29407  .  14 

171.485 

181| 

570.984 

25944.17 

161.072 

193| 

608.683 

29483.18 

171.707 

182 

571.769 

26015.59 

161.293 

194 

609.468 

29559.32 

171.928 

1821 

572.555 

26087.11 

161.515 

1941 

610.254 

29635  .  55 

172.150 

182^ 

573.340 

26158.73 

161.737 

1941 

611.039 

29711.88 

172.371 

182| 

574.126 

26230.45 

161.958 

194| 

611.825 

29788.31 

172.593 

183 

574.911 

26302.26 

162.180 

195 

612.610 

29864.84 

172.814 

1831 

575.696 

26374.17 

162.401 

1951 

613.395 

29941.46 

173.036 

1831 

576.482 

26446  .  19 

162.623 

1951 

614.181 

30018.19 

173.258 

183| 

577.267 

26519.29 

162.844 

195| 

614.966 

30095.01 

173.479 

184 

578.053 

26590.50 

163.066 

196 

615.752 

30171.93 

173.701 

1841 

578.838 

26662.81 

163.287 

1961 

616.537 

30248.95 

173.922 

1841 

579.623 

26735.21 

163.509 

196* 

617.322 

30326.06 

174.144 

184f 

580.409 

26807.71 

163.732 

196f 

618.108 

30403.28 

174.365 

185 

581.194 

26880.32 

163.952 

197 

618.893 

30480.59 

174.587 

1851 

581.980 

26953.01 

164.174 

1971 

619.679 

30588.00 

174.808 

1851 

582.765 

27025.81 

164.395 

1971 

620.464 

30635.51 

175.030 

185| 

583.550 

27098.71 

164.617 

197| 

621.249 

30713.12 

175.252 

186 

584.336 

27171.70 

164.838 

198 

622.035 

30790.82 

175.473 

1861 

585.121 

27244.79 

165.060 

1981 

622.820 

30868.63 

175.695 

1861 

585.907 

27317.98 

165.282 

198* 

623.606 

30946.53 

175.916 

186| 

586  .  692 

27391.27 

165.503 

198| 

624.391 

31024.53 

176.138 

187 

587.477 

27464.65 

165.725 

199 

625.176 

31102.63 

176.359 

1871 

588.263 

27538.14 

165.946 

1991 

625.962 

31180.82 

176.581 

1871 

589.048 

27611.72 

166.168 

1991 

626.747 

31259.12 

176.802 

187| 

589.834 

27685.40 

166.389 

199| 

627.533 

31337.49 

177.024 

200 

628.318 

31415.98 

177.246 

352 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


DECIMAL   EQUIVALENT   OF   AN   INCH. 


8ths. 

A  =  .5625 

H  =  .53125 

A 

=  .  140625 

tt  =.578125 

i  =.125 

ft  =  .6875 

ft  =  .59375 

tt 

=  .  171875 

if  =  .609375 

i  =  .250 

tt  =.8125 

ft  =  .65625 

if 

=  .203125 

tt  =  .640625 

t  =  .375 

if  =  .9375 

&  =  .71875 

if 

=  .234375 

if  =  .671875 

*  =  .500 

ft  =  .78125 

« 

=  .265625 

If  =  .703125 

*  =  .625 

32ds. 

ft  =  .84375 

if 

=  .296875 

tt  =  .734375 

f  =  .750 

A  =  .03125 

§*  =  .90625 

tt 

=  .328125 

tt  =  .  765625 

J  =  .875 

A  =  .09375 

ft  =  .96875 

If 

=  .359375 

tt  =  .796875 

A  =  •  15625 

if 

=  .390625 

tt  =.828125 

leths. 

A  =.21875 

64ths. 

tt 

=  .421875 

if  =.859375 

A  =  .  0625 

A  =  .28125 

A  =  .015625 

if 

=  .453125 

tt  =.890625 

A  =  .  1875 

ft  =  .  34375 

A  =  -046875 

if 

=  .484375 

if  =  .921875 

A  =  .3125 

ft  =  .  40625 

A  =  .078125 

H 

=  .515627 

it  =  .953125 

A  =  .4375 

H  =  .46875 

A  -  .109375 

if 

=  .546875 

H  =  .984375 

LOGARITHMS  OF  CONVENIENT  CONSTANTS. 
Compiled  by  J.  J.  Clark. 


Number. 

Logarithm. 

Reciprocal. 

Logarithm. 

TT  —  3  1416 

.4971509 

318309 

1  5028491 

-=  7854 

1  .  8950909 

1  273237 

1049091 

^ 
7r2  =  9.86965  

.9943018 

.  10132 

1  .  0056982 

VTT=  1  772457  

2485755 

.5641888 

1  7514245 

.11.=  564189.  . 

1  7514245 

1  .  772456 

2485755 

N* 
0  —  32  16 

1  5073160 

0310945 

2  4926840 

$0—16  08 

1  2062860 

06218906 

2  7937140 

20  —  6432 

1  8083460 

01554727 

2  1916540 

V^2g=  8.019974  
1  cu.  in.  water  weighs  .03617  Ibs.  .  . 
Water-column    l"Xl"Xl'  weighs 
43403  Ibs 

.9041730 
2.5583485 

1  6375197 

.  1246887 
27.64723 

2  303988 

1.0958270 
1.4416515 

3624803 

Water-column     1"    d.Xl'    weighs 
34088  Ibs 

1  5326015 

2  .  933584 

4673985 

1  Ib  .  water  =  column  1"  X  V  X  2.304' 
1  Ib.  water  =  column  1"  d.  X  2.9336' 
1  cu.  ft.  air  at  32°  F.  and  30"  Hg 
weighs  08073  Ibs 

.3624825 
.4674009 

2  9070350 

.4340278 
.340878 

12  387 

1.6375175 
1.5325991 

1   0929650 

1  gal  H  O  weighs  8  355  Ibs 

9219465 

11969 

1  0780535 

1  cu.  ft.  H2O  contains  7.48  gal  
147 

.8739016 
1  1673173 

.  13369 
06802721 

I  .  1260984 
2  8326827 

1728                      

3  2375437 

.0005787037 

4  .  7624563 

778       

2  .  8909796 

.001285347 

3.1090204 

144   .    

2.1583625 

.  00694445 

3.8416375 

12  

1.0791812 

.0833333 

2.9208188 

33000 

4  5185139 

0000303 

5  4814861 

MATHEMATICAL  TABLES. 


353 


LENGTHS  OF  CHORDS   FOR  SPACING  CIRCLE  WHOSE   DIAMETER  IS   1. 
For  Circles  of  other  Diameters  Multiply  Length  given  in  Table  by  Diameter  of  Circle. 


No.  of 
Spaces 

Length  of 
Chord. 

No.  of 
Spaces. 

Length  of 
Chord. 

No.  of 
Spaces. 

Length  of 
Chord. 

No.  of 

Spaces. 

Length  of 
Chord. 

26 

.1205 

51 

.0616 

76 

.0413 

27 

.1161 

52 

.0604 

77 

.0408 

3 

.8660 

28 

.1120 

53 

.0592 

78 

.0403 

4 

.7071 

29 

.1081 

54 

.0581 

79 

.0398 

5 

.5878 

30 

.1045 

55 

.0571 

80 

.0393 

6 

.5000 

31 

.1012 

56 

.0561 

81 

.0388 

7 

.4339 

32 

.0980 

57 

.0551 

82 

.0383 

8 

.3827 

33 

.0951 

58 

.0541 

83 

.0378 

9 

.3420 

34 

.0923 

59 

.0532 

84 

.0374 

10 

.3090 

35 

.0896 

L60 

.0523 

85 

.0370 

11 

.2817 

36 

.0872 

61 

.0515 

86 

.0365 

12 

.2588 

37 

.0848 

62 

.0507 

87 

.0361 

13 

.2393 

38 

.0826 

63 

.0499 

88 

.0357 

14 

.2225 

39 

.0805 

64 

.0491 

89 

.0353 

15 

.2079 

40 

.0785 

65 

.0483 

90 

.0349 

16 

.1951 

41 

.0765 

66 

.0476 

91 

.0345 

17 

.1838 

42 

.0747 

67 

.0469 

92 

.0341 

18 

.1736 

43 

.0730 

68 

.0462 

93 

.0338 

19 

.1646 

44 

.0713 

69 

.0455 

94 

.0334 

20 

.1564 

45 

.0698 

70 

.0449 

95 

.0331 

21 

.1490 

46 

.0682 

71 

.0442 

96 

.0327 

22 

.1423 

47 

.0668 

72 

.0436 

97 

.0324 

23 

.1362 

48 

.0654 

73 

.0430 

98 

.0321 

24 

.1305 

49 

.0641 

74 

.0424 

99 

.0317 

25 

.1253 

50 

.0628 

75 

.0419 

100 

.0314 

354  AMERICAN  GAS-ENGINEERING  PRACTICE. 

LOGARITHM   OF  NUMBERS   FROM   0  TO   1200. 


No. 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

Prop. 

0 

0 

00000 

30103 

47712 

60206 

69897 

77815 

84510 

90309 

95424 

10 

00000 

00432 

00860 

01284 

01793 

02119 

02531 

02938 

03342 

03743 

415 

11 

04139 

04532 

04922 

0530S 

05690 

06070 

06746 

06819 

07188 

07555 

379 

12 

07918 

08279 

08636 

08991 

09342 

09691 

10037 

10380 

10721 

11059 

344 

13 

11394 

11727 

12057 

12385 

12710 

13033 

13354 

13672 

13988 

14301 

323 

14 

14613 

14922 

15229 

15534 

15836 

16137 

16435 

16732 

17026 

17319 

298 

15 

17609 

17898 

18184 

18468 

18752 

19033 

19312 

19590 

19866 

20140 

281 

16 

20412 

20683 

20952 

21219 

21484 

21748 

22011 

22272 

22531 

22789 

264 

17 

23045 

23300 

23553 

23805 

24055 

24304 

24551 

24797 

25042 

25285 

249 

18 

25527 

25768 

26007 

26245 

26482 

26717 

26951 

27184 

27416 

27646 

234 

19 

27875 

28103 

28330 

28556 

28780 

29003 

29226 

29447 

29667 

29885 

222 

20 

30103 

30320 

30535 

30750 

30963 

31175 

31387 

31597 

31806 

32015 

212 

21 

32222 

32428 

32634 

32838 

33041 

33244 

33415 

33646 

33846 

34044 

202 

22 

34242 

34439 

34635 

34830 

35025 

35218 

35411 

35603 

35793 

35984 

193 

23 

36173 

36361 

36549 

36736 

37922 

37107 

37291 

37475 

37658 

37840 

185 

24 

38021 

38202 

38382 

38561 

38739 

38917 

39094 

39270 

39445 

39620 

177 

25 

39794 

39967 

40140 

40312 

40483 

40654 

40824 

40993 

41162 

41330 

170 

26 

41497 

41664 

41830 

41996 

42160 

42325 

42488 

42651 

42813 

42975 

164 

27 

43136 

43297 

43457 

43616 

43775 

43933 

44091 

44248 

44404 

44560 

158 

28 

44716 

44871 

45025 

45179 

45332 

45484 

45637 

45788 

45939 

46090 

153 

29 

46240 

46389 

46538 

46687 

46835 

46982 

47129 

47276 

47422 

47567 

148 

30 

47712 

47857 

48001 

48144 

48287 

48430 

48572 

48714 

48855 

48966 

143 

31 

49136 

49276 

49415 

49554 

49693 

49831 

49969 

50106 

50243 

50379 

138 

32 

50515 

50651 

50786 

50920 

51055 

51189 

51322 

51455 

51587 

51720 

134 

33 

51851 

51983 

52114 

52244 

52375 

52504 

52634 

52763 

52892 

53020 

130 

34 

53148 

53275 

53403 

53529 

53656 

53782 

53908 

54033 

54158 

54283 

126 

35 

54407 

54531 

54654 

54777 

54900 

55023 

55145 

55267 

55388 

55509 

122 

36 

55630 

55751 

55871 

55991 

56110 

56229 

56348 

56467 

56585 

56703 

119 

37 

56820 

56937 

57054 

57171 

57287 

57403 

57519 

57634 

57749 

57864 

116 

38 

57978 

58093 

58206 

58320 

58433 

58546 

58659 

58771 

58883 

58995 

113 

39 

59106 

59218 

59329 

59439 

59550 

59660 

59770 

59879 

59988 

60097 

110 

40 

60206 

60314 

60423 

60531 

60638 

60746 

60853 

60959 

61066 

61172 

107 

41 

61278 

61384 

61490 

61595 

61700 

61805 

61909 

62014 

62118 

62221 

104 

42 

62325 

62428 

62531 

62634 

62737 

62839 

62941 

63043 

63144 

63246 

102 

43 

63347 

63448 

63548 

63649 

63749 

63849 

63949 

64048 

64147 

64246 

99 

44 

64345 

64444 

64542 

64640 

64738 

64836 

64933 

65031 

65128 

65225 

98 

45 

65321 

65418 

65514 

65610 

65706 

65801 

65896 

65992 

66087 

66181 

96 

46 

66276 

66370 

66464 

66558 

66652 

66745 

66839 

66932 

67025 

67117 

95 

47 

67210 

67302 

67394 

67486 

67578 

67669 

67761 

67852 

67943 

68034 

92 

48 

68124 

£8215 

68305 

68395 

68485 

68574 

68664 

68753 

68842 

68931 

90 

49 

69020 

69108 

69197 

69285 

69373 

69461 

69548 

69636 

69723 

69810 

88 

50 

69897 

69984 

70070 

70157 

70243 

70329 

70415 

70501 

70586 

70672 

86 

51 

70757 

70842 

70927 

71012 

7109f> 

71181 

71265 

71349 

71433 

71517 

84 

52 

71600 

71684 

71767 

71850 

71933 

72016 

72099 

72181 

72263 

72346 

82 

53 

72428 

72509 

72591 

72673 

72754 

72835 

72916 

72997 

73078 

73159 

81 

Indices  of  Logarithms: 
Log.  4030  =  3.60530 
"      403  =  2.60530 


Log.  40.3  =  1.60530 
"  4.03=  .60530 
"  .403=  .60530 


Log.    .0403    = 
"       .00403= 


t. 60530 
r.  60530 


Find  Log.  of  5065 

Log.  of  5060 

Prop.  86  X  Diff.  5 


=  3.70415 
430 


Log.  required  =  3 . 704580 
Find  number  of  Log.  .  .  3. 771442 
Log.  of  5900=  3.770850 

iff.  592  -H  Prop.  73  =  8.    Diff.  =  592 
No.   required   5908 


MATHEMATICAL  TABLES. 

LOGARITHM  OF  NUMBERS   FROM  0  TO   1200— Con  tinned. 


355 


No. 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

Prop. 

54 

73239 

73320 

73400 

73480 

73560 

73670 

73719 

73799 

73878 

73957 

80 

55 

74036 

74115 

74194 

74273 

74351 

74429 

74507 

74586 

74663 

74741 

78 

56 

74819 

74896 

74974 

75051 

75128 

75205 

75282 

75358 

75435 

75511 

77 

57 

75587 

75664 

75740 

75815 

75891 

75967 

76042 

76118 

76193 

76268 

75 

58 

76343 

76418 

76492 

76567 

76641 

76716 

76790 

76864 

76938 

77012 

74 

59 

77085 

77159 

77232 

77305 

77379 

77452 

77525 

77597 

77670 

77743 

73 

60 

77815 

77887 

77960 

78032 

78104 

78176 

78247 

78319 

78390 

78462 

72 

61 

78533 

78604 

78675 

78746 

78817 

78888 

78958 

79029 

79099 

79169 

71 

62 

79239 

79309 

79379 

79449 

79518 

79588 

79657 

79727 

79796 

79865 

70 

63 

79934 

80003 

80072 

80140 

80209 

80277 

80346 

80414 

80482 

80550 

69 

64 

80618 

80686 

80754 

80821 

80889 

80956 

81023 

81090 

81158 

81224 

68 

65 

81291 

81358 

81425 

81491 

81558 

81624 

81690 

81757 

81823 

81889 

67 

66 

81954 

82020 

82086 

82151 

82217 

82282 

82347 

82413 

82478 

82543 

66 

67 

82607 

82672 

82737 

82802 

82866 

82930 

82995 

83059 

83123 

83187 

64 

68 

83251 

83315 

83378 

83442 

83506 

83569 

83632 

83693 

83759 

83822 

63 

69 

83885 

83948 

84011 

84073 

84136 

84198 

84261 

84223 

84386 

84448 

63 

70 

84510 

84572 

84634 

84696 

84757 

84819 

84880 

84942 

85003 

85065 

62 

71 

85126 

85187 

85248 

85309 

85370 

85431 

85491 

85552 

85612 

85673 

61 

72 

85733 

85794 

85854 

85914 

85974 

86034 

86094 

86153 

86213 

86273 

60 

73 

86332 

86392 

86451 

86510 

86570 

86629 

86688 

86747 

86806 

86864 

59 

74 

86923 

86982 

87040 

87099 

87157 

87216 

87274 

87332 

87390 

87448 

58 

75 

87506 

87564 

87622 

87680 

87737 

87795 

87852 

87910 

87967 

88024 

57 

76 

88081 

88138 

88196 

88252 

88309 

88366 

88423 

88480 

88536 

88593 

57 

77 

88649 

88705 

88762 

88818 

88874 

88930 

88986 

89042 

89098 

89154 

56 

78 

89209 

89265 

89321 

89376 

89432 

89487 

89542 

89597 

89653 

89708 

55 

79 

89763 

89818 

89873 

89927 

89982 

90037 

90091 

90146 

90200 

90255 

54 

80 

90309 

90363 

90417 

90472 

90526 

90580 

90634 

90687 

90741 

90795 

54 

81 

90849 

90902 

90956 

91009 

91062 

91116 

91169 

91222 

91275 

91328 

53 

82 

91381 

91434 

91487 

91540 

91593 

91645 

91698 

91751 

91803 

91855 

53 

83 

91908 

91960 

92012 

92065 

92117 

92169 

92221 

92273 

92324 

92376 

52 

84 

92428 

92480 

92531 

92583 

92634 

92686 

92737 

92788 

92840 

92891 

51 

85 

92942 

92993 

93044 

93095 

93146 

93197 

93247 

93298 

93349 

93399 

51 

86 

93450 

93500 

93551 

93601 

93651 

93702 

93752 

93802 

93852 

93902 

50 

87 

93952 

94002 

94052 

94101 

94151 

94201 

94250 

94300 

94349 

94399 

49 

88 

94448 

94498 

94547 

94596 

94645 

94694 

94743 

94792 

94841 

94890 

49 

89 

94939 

9*988 

95036 

95085 

95134 

95182 

95231 

95279 

95328 

95376 

48 

90 

95424 

95472 

95521 

95569 

95617 

95665 

95713 

95761 

95809 

95856 

48 

91 

95904 

95952 

95999 

96047 

96095 

96142 

96190 

96237 

96284 

96332 

48 

92 

96379 

96426 

96473 

96520 

96567 

96614 

96661 

96708 

96755 

96802 

47 

93 

96848 

96895 

96942 

96988 

97035 

97081 

97128 

97174 

97220 

97267 

47 

94 

97313 

97359 

97405 

97451 

97497 

97543 

97589 

97635 

97681 

97727 

46 

95 

97772 

97818 

97864 

97909 

97955 

98000 

98046 

98091 

98137 

98182 

46 

96 

98227 

98272 

98318 

98363 

98408 

98453 

98498 

98543 

98588 

98632 

45 

97 

98677 

98722 

98767 

98811 

98856 

98900 

98945 

98989 

99034 

99078 

45 

98 

99123 

99167 

99211 

99255 

99300 

99344 

99388 

99432 

99476 

99520 

44 

99 

99564 

99607 

99651 

99695 

99739 

99782 

99826 

99870 

99913 

99957 

44 

100 

00000 

00043 

00087 

00130 

00173 

00217 

90260 

00303 

00346 

00389 

43 

101 

00432 

00475 

00518 

00561 

00604 

00647 

00689 

00732 

00775 

00817 

43 

102 

00860 

00903 

00945 

00988 

01030 

01072 

01115 

01175 

01199 

01242 

42 

103 

01284 

01326 

01368 

01410 

01452 

01494 

01536 

01578 

01620 

01662 

42 

To  multiply  by  logarithms  add  the  logarithms  together  and  find  the  corresponding 
number. 

To  divide  by  logarithms  subtract  one  from  the  other. 

To  extract  the  root  divide  the  logarithm  by  the  index  of  the  root  and  find  the  num- 
ber corresponding  to  it. 

To  raise  a  number  to  any  power  multiply  the  logarithm  by  the  index  of  the  power 
and  find  the  corresponding  number. 


356 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


LOGARITHM   OF  NUMBERS   FROM   0  TO   1200— Continued. 


No. 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

Prop. 

104 

01703 

01745 

01787 

01828 

01870 

01912 

01953 

01995 

02036 

02078 

42 

105 

02119 

02160 

02202 

02243 

02284 

02325 

02366 

02407 

02449 

02490 

41 

106 

02531 

02572 

02612 

02653 

02694 

02735 

02776 

02816 

02857 

02898 

41 

107 

02938 

02979 

03019 

03060 

03100 

03141 

03181 

03222 

03262 

03302 

41 

108 

03342 

03383 

03423 

03463 

03503 

03543 

03583 

03623 

03663 

03703 

40 

109 

03743 

03782 

03822 

03S62 

03902 

0394] 

0398! 

04021 

04060 

04100 

40 

110 

04139 

04179 

04218 

04258 

04297 

04336 

04376 

04415 

04454 

04493 

39 

111 

04532 

01571 

04610 

04650 

04689 

04727 

04766 

Oi805 

04844 

04883 

39 

112 

04922 

04961 

04999 

05038 

05077 

05115 

05154 

05192 

05231 

05269 

39 

113 

05308 

05346 

05385 

05423 

05461 

05500 

05538 

05576 

05614 

05652 

38 

114 

05690 

05729 

05767 

05805 

05843 

05881 

05918 

05956 

05994 

06032 

38 

115 

00076 

0^108 

06145 

06183 

06221 

06258 

06296 

06333 

06371 

06408 

38 

116 

06446 

064S3 

06521 

06558 

06595 

06633 

06670 

06707 

06744 

06781 

37 

117 

06819 

068  6 

06893 

06930 

06967 

07004 

07041 

07078 

07115 

07151 

37 

118 

07188 

07225 

07262 

07298 

07335 

07372 

07408 

07445 

07482 

07518 

37 

119 

07555 

07591 

07628 

07644 

07700 

07737 

07773 

07809 

07846 

07882 

36 

INVOLUTION  AND  EVOLUTION  or  FRACTIONS  BY  LOGARITHMS. 

In  a  logarithm  the  integer  is  called  the  characteristic,  and  the  decimal  portion  the  man- 
tissa. 

INVOLUTION. — The  number  carried  from  the  mantissa  to  the  characteristic  being  posi- 
tive, must  be  deducted  from  the  negative  characteristic . 

Example. — Find  the  5th  power  of  .05.  or  the  value  of  .05s. 

Log.  .05  =  2  .J>9897 

then  2X5    =10 
+ 
and  .69897X5  =  3.49485 


Then  log.  .05s  =  7. 49485 

and  .055  =  .0000003125 

EVOLUTION. — If  the  negative  characteristic  be  not  divisible  without  a  remainder  by 
the  index  of  the  required  root,  the  number  of  units  sufficient  to  make  it  so  divisible  must 
be  added  to  it,  and  the  same  number  of  units  must  also  be  added  to  the  mantissa  before 
division. 

Example. — Find  the  value  of  ^.0000003125. 
Log.  .00000031 25  =  7. 49485_ 

then  7  +  3=-- 10,  and  10-5-2 
and  3. 49485- 5=    . 


3.03654 
1.83442 


Therefore  log.       .0000003125  =  2. 69897  =  log.  of  .05. 

PROPORTION  BY  LOGARITHMS. 

Add  together    the  logarithms  of  the  2d  and    3d  terms,  and   from  jtheir  sum    subtract 
the  logarithm  of  the  first  term,  then  the  number  corresponding  to  the  logarithm  of  fhe 
remainder  gives  the  required  answer. 
Example.—  68.30  :  13.70  :  :  79.40  :  ? 

Log.  13.70  =  1.13672 
Log.  79. 40-1. 

Sum 
Log.  68.30  = 

Diff.   1.20212  =  log.  of  15.93. 

The  common  logarithm  of  any  number  is  the  power  to  which,  if  10  be  raised,  the  said 
number  is  the  result,  thus: 

102  =  100  therefore  log.  =•=  2. 

1(VM2        =  263         "  r   =  2.42 

]0-2-42   =  .0263     "  "     =  2.42 

To  multiply  by  the  aid  of  logarithms —  add  the  logarithms  of  the  numbers  together  and 
find  the  corresponding  number  of  the  logarithm  obtained. 

TO  divide  by  the  aid  of  logarithms — subtract  one  logarithm  from  the  other. 
To  extract  any  root— divide  the  logarithm  by  the  index  of  the  root  and  find  the  corre- 
sponding number  of  the  logarithm  obtained. 

To  raise  a  number  to  any  power — multiply  the  logarithm  of  the  Number  by  the  index 
of  the  power,  and  find  the  corresponding  number  of  the  logarithm  obtained. 

To  find  proportion  by  the  aid  of  logarithms — add  together  the  logarithms  of  the  second 
and  third  ter^is  and  subtract  th«  logarithm  of  the  first  term;  the  answer  is  the  correspond- 
ing number  of  the  logarithm  obtained. 


MATHEMATICAL  TABLES. 


357 


VALUES  OF  SQUARES,  CUBES,  SQUARE  ROOTS,  AND  CUBE  ROOTS  OF 
NUMBERS   1   TO   100. 


No. 

Square. 

Cube. 

Square 
Root. 

Cube 
Root. 

No. 

Square. 

Cube. 

Square 
Root. 

Cube 

Root. 

1 

1 

1 

1.0 

1.0 

51 

2601 

132651 

7.14143 

3.7084 

2 

4 

8 

1.41421 

1.2599 

52 

2704 

140608 

7.21110 

3.7325 

3 

9 

27 

1.73205 

1.4422 

53 

2809 

148877 

7.28011 

3.7563 

4 

16 

64 

2.0 

1.5874 

54 

2916 

157464 

7.34847 

3.7798 

5 

25 

125 

2.23607 

1.7100 

55 

3025 

166375 

7.4162 

3.8030 

6 

36 

216 

2.44949 

1.8171 

56 

3136 

175616 

7.48331 

3.8259 

7 

49 

343 

2  .  64575 

1.9129 

57 

3249 

185193 

7.54083 

3.8485 

8 

64 

512 

2.82843 

2.0 

58 

3364 

195112 

7.61577 

3.8709 

9 

81 

729 

3.0 

2.0801 

59 

3481 

205379 

7.68115 

3.8930 

10 

100 

1000 

3.16228 

2.1544 

60 

3600 

216000 

7.74597 

3.9149 

11 

121 

1331 

3.31662 

2.2240 

61 

3721 

226981 

7.81025 

3.9365 

12 

144 

1728 

3.46410 

2.28P4 

62 

3844 

238328 

7.87401 

3.9579 

13 

169 

2197 

3.60555 

2.3513 

63 

3969 

250047 

7.93725 

3.9791 

14 

196 

2744 

3.74166 

2.4101 

64 

4096 

262144 

8.0 

4.0 

15 

225 

3375 

3.87298 

2.4662 

65 

4225 

274625 

8.06226 

4.0207 

16 

256 

4096 

.0 

2.5198 

66 

4356 

287496 

8.12404 

4.0412 

17 

289 

4913 

.12311 

2.5713 

67 

4489 

300763 

8.18535 

4.0615 

18 

324 

5832 

.  24264 

2  .  6207 

68 

4624 

314432 

8.24621 

4.0817 

19 

361 

6859 

.  35*90 

2.6684 

69 

4761 

328509 

8.30662 

4.1016 

20 

400 

8000 

.47214 

2.7144 

70 

4900 

343000 

8  .  36660 

4.1213 

21 

441 

9261 

.58258 

2.7589 

71 

5041 

357911 

8.42615 

4.1408 

22 

484 

10648 

.  69042 

2.8020 

72 

5184 

373248 

8.48528 

4.1602 

23 

529 

.12167 

.79583 

2.8439 

73 

5329 

389017 

8.54400 

4.1793 

24 

576 

13824 

.89898 

2  .  8845 

74 

5476 

405224 

8.60233 

4.1983 

25 

625 

15625 

5.0 

2.9240 

75 

5625 

421875 

8.66025 

4.2172 

26 

676 

17576 

5.09902 

2.9625 

76 

5776 

438976 

8.71780 

4.2358 

27 

729 

19683 

5.19615 

3.0 

77 

5929 

456533 

8.77496 

4.2543 

28 

784 

21952 

5.29150 

3.0366 

78 

6084 

474552 

8.83176 

4.2727 

29 

841 

24389 

5.38516 

3.0723 

79 

6241 

493039 

8.88819 

4.2908 

30 

900 

27000 

5.47723 

3.1072 

80 

6400 

512000 

8.94427 

4.  3089 

31 

961 

29791 

5.56776 

3.1414 

81 

6551 

531441 

9.0 

4.3267 

32 

1024 

32768 

5.65685 

3.1748 

82 

6724 

551368 

9.05539 

4.3445 

33 

1089 

35937 

5.74456 

3.2075 

83 

6889 

571787 

9.11043 

4.3621 

31 

1156 

39304 

5.83095 

3.2396 

84 

7056 

592704 

9.16515 

4.3795 

35 

1225 

42875 

5.91608 

3.2711 

85 

7225 

614125 

9.21954 

4.3968 

36 

1296 

46656 

6.0 

3.3019 

86 

7396 

636056 

9.27362 

4.4140 

37 

1309 

50653 

6.08276 

3  .  3322 

87 

7569 

658503 

9.32738 

4.4310 

38 

1444 

54872 

6.16441 

3.S620 

88 

7744 

681472 

9  .  38082 

4.4480 

39 

1521 

59319 

6.245 

3.3912 

89 

7921 

704969 

9.43398 

4.4647 

40 

1600 

64000 

6.3245G 

3.4200 

90 

8100 

729000 

9.48683 

4.4814 

41 

1681 

68921 

6.40312 

3.4482 

91 

8281 

753571 

9.53939 

4.4979 

42 

1764 

74088 

6.48074 

3.4760 

92 

8464 

778688 

9.59166 

4.5144 

43 

1849 

79507 

6.55744 

3.5034 

93 

8649 

804357 

9.64365 

4.5307 

44 

1936 

85184 

6  .  63325 

3.5303 

94 

8836 

830584 

9.69536 

4  .  5468 

45 

2025 

91125 

6.70820 

3.5569 

95 

9025 

857375 

9  .  74679 

4.5629 

46 

2116 

97336 

6.78133 

3  .  5830 

96 

9216 

884736 

9  .  79796 

4.5789 

47 

2209 

103823 

6.85565 

3.6088 

97 

9409 

912573 

9.84886 

4.5947 

48 

2304 

110592 

6.92820 

3.6342 

98 

9604 

941192 

9.89949 

4  .  6104 

49 

2401 

117649 

7.0 

3.6593 

99 

9801 

970299 

9.94987 

4  .  6261 

50 

2500 

125000 

7.07107 

3.6840 

100 

10000 

1000000 

10.0 

4.6416 

358 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


VALUES  OF  n-K  AND 


FOR  NUMBERS  FROM  1  TO  100. 


n 

nn 

"1 

n 

nn 

«*r 

n 

UK 

"1 

1.0 

3.142 

0.7854 

2(5.0 

81.681 

530.93 

52.0 

1()3.36 

2123.72 

1.5 

4.712 

1.7672 

26.5 

83.252 

551.55 

53.0 

166.50 

2206.19 

2.0 

6.283 

3.1416 

27.0 

84.823 

572.56 

54.0 

169.64 

2290.22 

2.5 

7.  854 

4.9087 

27.5 

86.394 

593.96 

55.0 

172.78 

2375.83 

3.0 

9.425 

7.0686 

28.0 

87.965 

615.75 

56.0 

175.93 

2463.01 

3.5 

10.996 

9.6211 

28.5 

89  .  535 

637.94 

57.0 

179.07 

2551.76 

4.0 

12.566 

12.566 

29.0 

91.106 

660.52 

58.0 

182.21 

2642.08 

4.5 

14.137 

15.904 

29.5 

92.677 

683.49 

59.0 

185.35 

2733.97 

5.0 

15.708 

19.635 

30.0 

94.248 

706.86 

60.0 

188.49 

2827.44 

5.5 

17.279 

23.758 

30.5 

95.819 

730.62 

61.0 

191.63 

2922.47 

6.0 

18.850 

28.274 

31.0 

97.389 

754.77 

62.0 

194.77 

3019.07 

6.5 

20.420 

33  .  183 

31.5 

98.960 

779.31 

63.0 

197.92 

3117.25 

7.0 

21.991 

38.485 

32.0 

100.53 

804.25 

64.0 

201  .  06 

3216.99 

7.5 

23.562 

44.179 

32.5 

102.10 

829.58 

65.0 

204  .  20 

3318.31 

8.0 

25.133 

50.266 

33.0 

103.67 

855.30 

66.0 

207.34 

3421.20 

8.5 

26.704 

56.745 

33.5 

105.24 

881.41 

67.0 

210.48 

3525.66 

9.0 

28.274 

63.617 

34.0 

106.81 

907.92 

68.0 

213.63 

3631.69 

9.5 

29.845 

70.882 

34.5 

108.38 

934.82 

69.0 

216.77 

3739.29 

10.0 

31.416 

78.540 

35.0 

109.96 

962.11 

70.0 

219.91 

3848  .  46 

10.5 

32.987 

86.590 

35.5 

111.53 

989.80 

71.0 

223.05 

3959.20 

11.0 

34.558 

95.033 

36.0 

113.10 

1017.88 

72.0 

226.19 

4071.51 

11.5 

36.128 

103.87 

36.5 

114.67 

1046.35 

73.0 

229.33 

4185.39 

12.0 

37.699 

113.10 

37.0 

116.24 

1075.21 

74.0 

232.47 

4300.85 

12.5 

39.270 

122.72 

37.5 

117.81 

1104.47 

75.0 

235.62 

4417.87 

13.0 

40.841 

132.73 

38.0 

119.38 

1134.11 

76.0 

238.76 

4536.47 

13.5 

42.412 

143.14 

38.5 

120.95 

1164.16 

77.0 

241.90 

4656.63 

14.0 

43.982 

153.94 

39.0 

122.52 

1194.59 

78.0 

245.04 

4778.37 

14.5 

45.553 

165.13 

39.5 

124.09 

1225.42 

79.0 

248.18 

4901  .  68 

15.0 

47.124 

176.72 

40.0 

125.66 

1256.64 

80.0 

251.32 

5026.56 

15.5 

48.695 

188.69 

40.5 

127.23 

1288.25 

81.0 

254.47 

5153.01 

16.0 

50.265 

201  .  06 

41.0 

128.81 

1320.25 

82.0 

257.61 

5281.03 

16.5 

51.836 

213.83 

41.5 

130.38 

1352.65 

83.0 

260.75 

5410.62 

17.0 

53  .  407 

226.98 

42.0 

131.95 

1385.44 

84.0 

263.89 

5541.78 

17.5 

54.978 

240.53 

42.5 

133.52 

1418.63 

85.0 

267.03 

5674.50 

18.0 

56.549 

254.47 

43.0 

135.09 

1452.20 

86.0 

270.17 

5808.81 

18.5 

58.119 

268.80 

43.5 

136.66 

1486.17 

87.0 

273.32 

5944.69 

19.0 

59.690 

283.53 

44.0 

138.23 

1520.53 

88.0 

276.46 

6082.13 

19.5 

61.261 

298.65 

44.5 

139.80 

1555.28 

89.0 

279.60 

6221.13 

20.0 

62.^32 

314.16 

45.0 

141.37 

1590.43 

90.0 

282.74 

6361.74 

20.5 

64.403 

320.06 

45.5 

142.94 

1625.97 

91.0 

285.88 

6503.89 

21.0 

65.973 

346.36 

46.0 

144.51 

1661.90 

92.0 

289.02 

6647.62 

21.5 

67.544 

363.05 

46.5 

146.08 

1698.23 

93.0 

292.17 

6792.92 

22.0 

69.115 

380.13 

47.0 

147.65 

1734.94 

94.0 

295.31 

6939  .  78 

22.5 

70.686 

397.61 

47.5 

149.23 

1772.05 

95.0 

298.45 

7088.23 

23.0 

72.257 

415.48 

48.0 

150.80 

1809.56 

96.0 

301.59 

7238.24 

23.5 

73.827 

433.74 

48.5 

152.37 

1847.45 

97.0 

304.73 

7389.83 

24.0 

75.398 

452.39 

49.0 

153.94 

1885.74 

98.0 

307.87 

7542.98 

24.5 

76.969 

471.44 

49.5 

155.51 

1924.42 

99.0 

311.02 

7697.68 

25.0 

78.540 

490.87 

50.0 

157.08 

1963.50 

100.0 

314.16 

7854.00 

25.5 

80.111 

510.71 

51.0 

160.22 

2042.82 

MATHEMATICAL  TABLES. 


359 


IMPORTANT  VALUES  OF   x. 


=  3.14159 

Log. 
0.4971499" 

^*  =  1.46459 

Log. 
0  .  1657160" 

=  0.10132 

=  9.8696 

1.0056952" 
0.9942996" 

—  -0.31831 

7C 

V—  =0.54619 

•n 

3.5028503" 
I.  7373437" 

-  1.77245 

0.2485749" 

^-=0.785398 

1.8950899'* 

=  31.00628 

1.4914496" 

-|  =  0.52359 

I.  7189986" 

AREAS  AND  VOLUMES  OP  BODIES. 

Volume  of  rectangular  vessel  =  o6c,  where  a,  6  and  c  are  the  three  dimensions. 
Area  of  triangle  =  £  base  X  height. 

Area  of  circle ^d2=xr2.     r  =  radius.    —=0.7851. 

Area  of  ellipse  =  trans  verse  axisX  .  7854  X  con  jugate  axis=»ra&,  where  a  and  &  are  lengths 
of  the  two  semi-axes. 

Surface  of  sphere  =?rd2  =  4;rr2.     d  =  diameter.     4^  =  12.5664. 

Surf  ace  of  cy  Under  =  area  of  both  ends  X  length  X  diameter. 

Surface  of  cone  =  area  of  base  +  circumference  of  baseXi  slant  height. 

Volume  of  sphere=°4>rt*.    |*  =  4. 1888=^X0. 5236,  i.e.,  -|<#. 

66  o 

Volume  of  cylinder  =xr2h.     r  —  radius  of  base,     h  =  height. 
Volume  of  cone  or  pyramid  =  area  of  baseXi  perpendicular  height. 

Volume   of    frustum   of   cone  =  0.26 18  H(D*+cP+Dd)t  where  D  and  d  =  diameters  of 
each  end,  and  H  =  perpendicular  height. 

Volume  of  cask  considered  as  middle  frustum  of  a  prolate  spheroid: 


D  =  diameter  of  cylinder  equal  in  volume  and  length  to  cask. 
B  =  diameter  at  bung.     H  (or  H ')  =  diameter  at  head. 

Or  (approximately) : 

Ascertain  the  difference  between  B  and  H,  and  multiply  it  by  .7  (or  .68  if  less  than  6 
inches);  add  the  product  to  H  to  obtain  diameter  of  required  cylinder. 
Or 

Capacity  in  gallons  =.  00141 02  L(HH'  +  B2). 
L  =  length. 
All  the  measurements  are  of  course  internal. 

PHYSICAL. 
To  convert 

Degrees  of  Twaddle's  hydrometer  into  S.G.    (water  =  1000),  multiply  by  5,  and  add 

S.G.  (water  =  1000)  into  degrees  Twaddle,  subtract  1000,  and  divide  by  5. 
S.G.,  air-lto8.G.,#-l,  multiply  by  14.43S. 
S.G.,  H  =  1  to  S.G.,  air  =  l,  multiply  by  0.06926. 

Weight  in  air  to  weight  in  vacuo: 
P  =  weight  required  in  vacuo. 
q  =  weight  in  air. 
V  =  volume  of  body  weighed. 
v^=  volume  of  the  weignts. 
«  =  specific  gravity  of  air  (weight  of  one  cubic  unit). 


360 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE  SHOWING  THE  AREAS  OF  CIRCLES  IN   IMPERIAL  GALLONS  CORRE- 
SPONDING   TO    DIAMETERS    IN  IMPERIAL  INCHES. 

By  the  area  in  gallons  is  meant  the  number  of  gallons  which  are  contained  by  a  cylin- 
der having  the  circle  as  base,  and  a  height  of  one  inch.     This  table  can  be  employed  for 

calculating  the  area  of  ellipses,  according  to  the  formula  Area=— — ~9  a~ — ,  where  a  is 

the  area  of  the  circle,  having  the  transverse  diameter  of  the  ellipse  as  its  diameter, 
B  the  area  of  corresponding  circle  for  the  congregate  diameter,  and  (a—B}  the  area  of 
R  circle  having  the  difference  between  the  transverse  and  congregate  diameters  as  its 
diameter,  the  various  diameters  being  expressed  in  inches. 


Diam.  in  Ins. 

0 

1 

2 

3 

4 

5 

6 

7 

S 

9 

1 

.002s 

.0034 

.0040 

.0047 

.0055 

.0063 

.0072 

.0081 

.0091 

.0102 

2 

.0113 

.0124 

.0137 

.  0149 

.0163 

.0177 

.0191 

.0206 

.0222 

.0238 

3 

.0254 

.0272 

.0290 

.0308 

.0327 

.0346 

.0367 

.0387 

.0409 

.0430 

4 

.0153 

.0476 

.0499 

.0523 

.0548 

.0573 

.0599 

.0625 

.0652 

.0680 

5 

.0708 

.0736 

.0765 

.0795 

.0825 

.0856 

.0888 

.0920 

.0952 

.0986 

6 

.1019 

.1053 

.  1088 

.1124 

.1160 

.1196 

.1233 

.1271 

.1309 

.  1348 

7 

.1387 

.1427 

.1468 

.1509 

.1551 

.1593 

.1636 

.1679 

.1723 

.1767 

8 

.181? 

.1858 

.1901 

.  1951 

.1998 

.2046 

.2094 

.2143 

.2193 

.2243 

9 

.2204 

.2345 

.2397 

.2449 

.2502 

.2556 

.2610 

.2665 

.2720 

.2776 

10 

.2832 

.2889 

.2947 

.3005 

.3063 

.3122 

.3182 

.3243 

.3303 

.3365 

11 

.3427 

.3490 

.3553 

.3616 

.3681 

.3746 

.3811 

.3877 

.3944 

.4011 

12 

.4078 

.4147 

.4215 

.  4285 

.4355 

.4425 

.4496 

.4568 

.4640 

.4713 

13 

.4787 

.4860 

.4935 

.5010 

.5086 

.5162 

.5239 

.5316 

.5394 

.5472 

14 

.5551 

.5631 

.5711 

.5792 

.5873 

.5955 

.6037 

.6120 

.6204 

.6288 

15 

.6373 

.6458 

.6544 

.6630 

.6717 

.6805 

.6893 

.6982 

.7071 

.7161 

16 

.7251 

.7342 

.7433 

.7525 

.7618 

.7711 

.7805 

.7899 

.7994 

.8090 

17 

.8186 

.8282 

.8379 

.8477 

.8575 

.8674 

.8774 

.8874 

.8974 

.9075 

18 

.9177 

.9279 

.9382 

.9485 

.9589 

.9694 

.9799 

.9905 

.0011 

.0118 

19 

1.0225 

.0333 

1.0441 

1.0551 

.0660 

.0770 

1.0881 

1.0992 

.1104 

.1217 

20 

1.1330 

.1443 

1.1558 

1.1672 

.1788 

.1903 

.2020 

1.2137 

.2254 

.2372 

21 

1.2491 

.2610 

.2730 

1.2851 

.2972 

.3093 

.3215 

1  .3338 

.3461 

.3585 

22 

1.3709 

.3834 

.3960 

1.4086 

.4212 

.4339 

.4467 

1.4595 

.4724 

.4854 

23 

1.4984 

.5114 

1.5246 

1.5377 

.5510 

.5642 

.5776 

1.5910 

.6044 

.6179 

24 

1.6315 

.6451 

.5588 

1.6726 

.6863 

7002 

.7141 

1.7281 

.7421 

1.7562 

25 

1.7703 

.7845 

.7987 

1.8131 

1.8274 

1.8418 

1.8563 

1.8708 

.8854 

1.9001 

26 

1.9148 

1.9295 

1.9443 

1.9592 

1.9741 

1.9891 

2.0042 

2.0193 

2.0344 

2.0496 

27 

2.0049 

2.0802 

2.0956 

2.1110 

2.1265 

2.1421 

2.1577 

2.1734 

2.1891 

2.2049 

28 

2.2207 

2.2366 

2.2525 

2.2685 

2.2846 

2.3007 

2.3169 

2.3331 

2.3494 

2.3657 

29 

2.3821 

2.39S6 

2.4151 

2.4317 

2.4483 

2.4650 

2.4817 

2.4985 

2.5154 

2.5323 

30 

2.5473 

2.5663 

2.5834 

2.6005 

2.6177 

2.6349 

2.6523 

2.6696 

2.6870 

2.7045 

31 

2.7221 

2.739P 

2.7573 

2.7750 

2.7928 

2.8106 

2.8284 

2.8464 

2.8644 

2.8824 

32 

2.9005 

2.9187 

2.9369 

2.9551 

2.9735 

2.9919 

3.0103 

3.0288 

3.0473 

3.0660 

33 

3.0846 

3.1033 

3.1221 

3.1410 

3.1599 

3.1788 

3.1978 

3.2169 

3.2360 

3.2552 

34 

3.2744 

3.2937 

3.3130 

3.3324 

3.3519 

3.3714 

3.3910 

3.4106 

3.4303 

3  4500 

35 

3.4698 

3.4897 

3.5096 

3.5296 

3.5496 

3.5697 

3.5898 

3.6100 

3.6303 

3.6506 

36 

3.6710 

3.6914 

3.7119 

3.73?4 

3.7520 

3.7736 

3.7943 

3.8151 

3.8359 

3.8568 

37 

3.8777 

3.8987 

3.9198 

3.9409 

3.9620 

3.9833 

4.0045 

4.0259 

4.0472 

4.0687 

38 

4.0902 

4.1117 

4.1334 

4.1550 

4.1767 

4.1985 

4.2204 

4.2423 

4.2642 

4.2862 

39 

4.3083 

4.3304 

4.3526 

4.3748 

4.3971 

4.4195 

4.4419 

4.4643 

4.4869 

4.5094 

40 

4.5321 

4.5548 

4.5775 

4.6003 

4.6232 

4.6461 

4.6690 

4.6921 

4.7152 

4.7383 

41 

4.7615 

4.784S 

4.8081 

4.8314 

4.8549 

4.8783 

4.9019 

4.9255 

4.9491 

4.9728 

42 

4.9966 

5.0201 

5.0443 

5.0682 

5.0922 

5.1163 

5.1404 

5.1645 

5.1888 

5.2130 

43 

5.2374 

5.2618 

5.2862 

5.3107 

5.3353 

5.3599 

5.3846 

5.4093 

5.4341 

5.4589 

44 

5.483S 

5.50SS 

5.533S 

5.55S8 

5.5S40 

5.6091 

5.6344 

5.6597 

5.6850 

5.7104 

45 

57359 

5.7614 

5.7870 

5.8126 

5.8383 

5.8641 

5.8899 

5.9157 

5.9417 

5.9676 

MATHEMATICAL  TABLES. 


361 


AREAS  OF  CIRCLES   IN   IMPERIAL  GALLONS   FROM  DIAMETERS— Continued. 


Diam.  in  Ins. 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

46 

5.9937 

6.0198 

6.0459 

6.0721 

6.0984 

6.1247 

G.1510 

6.1775 

6.2040 

6.2305 

47 

6.2571 

6.2838 

6.3105 

6.3372 

6.3641 

6.3909 

6.4179 

6.4449 

6.4719 

6.4990 

48 

6.5262 

6.5534 

6.5807 

6.6080 

6.6354 

6.6629 

6.6904 

6.7179 

6.7455 

6.7732 

49 

6.8010 

6.8287 

6.8566 

6.8845 

6.9124 

6.9405 

6.9685 

6.9967 

7.0248 

7.0531 

50 

7.0814 

7.1097 

7.1381 

7.1666 

7.1951 

7.2237 

7.2524 

7.2810 

7.3098 

7.3386 

51 

7.3675 

7.3964 

7.4254 

7.4544 

7.4835 

7.5126 

7.5418 

7.5711 

7.6004 

7.6298 

52 

7.6592 

7.6887 

7.7183 

7.7479 

7.7775 

7.8072 

7.8370 

7.8668 

7.S967 

7.9265 

53 

7.9566 

7.9867 

8.0163 

8.0170 

8.0772 

8.1075 

8.1378 

8  1682 

8.1987 

8.2292 

54 

8.2597 

8.2903 

8.3210 

8.351S 

8.3825 

8.4134 

8.4443 

8.4753 

8.5063 

8.5373 

55 

8.5685 

8.5997 

8.6309 

8.6622 

8.693. 

8.7250 

8.7564 

8.7880 

8.8196 

8.8512 

56 

8.8829 

8.9146 

8.9465 

8.9783 

9.0102 

9.0422 

9.0743 

9.1064 

9.1385 

9.1707 

57 

9.2030 

9.2353 

9.2677 

9.3001 

9.332] 

9.3651 

9.3977 

9.4301 

9.4631 

9.4959 

58 

9.5287 

9.5816 

9.5945 

9.6275 

9.660:] 

9.6937 

9.7269 

9.7601 

9.7934 

9.8267 

59 

9.8601 

9.8933 

9.927J 

9.9807 

9.9943 

10.0280 

10.0617 

10.0995 

10.1293 

10.1632 

60 

10.1972 

10.2312 

10.2653 

10.2994 

10.3336 

10.3679 

10.4022 

10.4365 

10.4709 

10.5054 

61 

10.5399 

10  5745 

10.6092 

10.6439 

10.6786 

10.7134 

10.7483 

10.7832 

10.8182 

10.8533 

62 

10.S884 

10.9235 

10.9537  10.9940 

11.0293  11.0647 

11.  1001;  11.  1356 

11.1712 

11.2068 

63 

11.2424 

11.2781 

11.3139 

11.3497 

11.3356  11.4216 

11.4576  11.4936 

11.5293 

11.5659 

64 

11.6022 

11.6334 

11.6748 

11.7112 

11.7476  11.7842 

11.8207 

11.8573 

11.8940 

11.9308 

65 

11.9676 

12.0044 

12.0413 

12.0783 

12.1153 

12.1524 

12.1895 

12.2267 

12  2640 

12.3013 

66 

12.3386 

12.3760 

12.4135 

12.4511 

12.4886 

12.5263 

12.5640 

12.6017 

12.6396 

12.8774 

67 

12.7154 

12.7533 

12.7914 

12.8295 

12.8676 

12.9058 

12.9441 

12.9824 

13.0203 

13.0593 

68 

13.0978 

13.1353 

13.1749 

13.2136 

13.2523 

13.2911 

13.  3299'  13.3388 

13.407,^ 

13.4468 

69 

13.4853 

13.52  49 

13.5641 

13.6033 

13.0126 

13.6320 

13.72141  13.7603 

13.8003 

13  8399 

70 

13.8795 

13.9192 

13.9590 

13.993S 

14.0386 

14.0785 

14.1185 

14.1585 

14.1986 

14.2387 

71 

14.27S9 

14.3192 

14.3595 

14.3999 

14.4403 

14.480S 

14.5213 

14.5819 

14.6025 

14.6432 

72 

14.6840 

14.7248 

14.7657 

14.8036 

14.8476 

14.8886 

14.9297,  14.9709 

15.0121 

15.0534 

73 

15.0947 

15.1361 

15.1775 

15.2190 

15.2606J  15.3022 

15.343915.3356 

15.4274 

15.4692 

74 

15.5111 

15.5531 

15.5951 

15.6371 

15.6792J  15.  7214 

15.70371  15.8059 

15.8483 

15.8907 

75 

15.9332 

15.9757 

15.0182 

16.0609 

16.1036 

16.1463 

16.1891 

16.2320 

16.2749 

16.3179 

76 

16.3609 

16.  40  JO 

16.4471 

16.4903 

16.5336 

16.5769 

16.6202 

16.6637 

16.7071 

16.7507 

77 

16.7943 

16.8379 

16.8816 

16.9254 

16.9092 

17.0131 

17.0570  17.1010 

17.1450 

17.1891 

78 

17.2333 

17.2775 

17.3218 

17.3661 

17.4105 

17.4550 

17.4995  17.5440 

17.5386 

17.0333 

79 

17.6780 

17.7228 

17.7676 

17.8125 

17.8575 

17.9025 

17.9478  17.9927 

18.0379 

18.0831 

80 

18.1284 

18.1738 

18.2192 

18.2646 

18.3101 

18.3557 

18.4013 

18.4470 

18.4928 

18.5386 

81 

18.5S44 

13.6301 

18.6763 

18.7224 

18.7684 

18.8146 

18.8608 

18.9079 

18.9534 

18.9997 

82 

19.0462 

10.0926 

19.1392 

19.1858 

19.2324 

19.2791 

19.3259:19.3727 

19.4198 

19.4665 

83 

19.5135 

19..C608 

19.6077 

19.6548 

19.7021 

19.7493 

19.7967  19.8441 

19.8915 

19.9390 

84 

19.9860 

20.0342 

20.0819 

20.1296 

20.1774 

20.2252 

20.2731  20.3211 

20.3691 

20.4171 

85 

20.4653 

20.5135 

20.5617 

20.6100 

20.6583 

20.7007 

20.7552 

20.8037 

20.8523 

20.9096 

86 

20.9198 

20.9934 

21.0172 

21.0961 

21.1450 

21.1940 

21.2430 

21.2921 

21.3412 

21.3904 

87 

21.4397 

21.4890 

21.5384 

21  .5878 

21.6373J21.686S 

21.7364  21.7861 

21.8358 

21.8856 

88 

21.935* 

21  .9853 

21  0352 

22.0852 

22.  1352  122.  1854 

22.2355  22.2857 

22.3360 

22.3863 

89 

22.4367 

22.4872 

22.5377 

22.5883 

22.6389  22.6895 

22.740322.7911 

22.8419 

22.8928 

90 

22.9138 

22.9948 

23.0459 

23.0970 

23.1482 

23.1994 

23.2507 

23.3021 

23.3535 

23.4049 

91 

23.4565 

23.50SO 

23.5597 

23.6114 

23.6631 

23.7149 

23.7668 

23.8187 

23.8707 

23.9227 

92 

23.974S 

24.0270 

24.0792 

24.1314 

24.1838 

24.2361 

24.288624.3411 

24.39S6 

24.4462 

93 

24.4939 

21.5516 

24.6043 

24.6572 

24.7100 

24.7630 

24.8160  24.8690 

24.9222 

24.9753 

94 

25.02S5 

25.0S18 

25.1352 

25.1886 

25.2420  25.2955 

25.3491  25.4027 

25.4564 

25.5101 

95 

25.5639 

25.6177 

25.6717 

25  7256 

25.779025.8337 

25.8878 

25.9420 

25.9963 

25.0506 

96 

26.1049 

26.1593 

26.213? 

26.2683 

26.3229l26.3776 

20.4323  20.4870 

26.5418 

26.5967 

97 

26.6516 

26.7C66 

26.7610 

26.^167 

26.8719^26.9271 

26.9823  27.0377 

27.0930 

27.1485 

98 

27.2040 

27.2595 

27.3151J27.3708 

27.4265,27.4823 

27.5381  27.5940 

27.6499 

27.7059 

99 

27.7620 

27.8181 

27.8743i  27.9305 

27.9868I28.0431 

28.0995  28.1500 

28.2125 

28.2690 

100 

28.3257 

28.3823 

28.4391  28.4959 

28.5527  28.6096 

28.6666  28.7236 

28.7807 

28.8378 

362 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


AREAS   OF  CIRCLES  IN   IMPERIAL  GALLONS   FROM   DIAMETERS—  Continued. 


Diam.  in  Ins. 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

101 

28.8950 

28.9522 

29.0096 

29.0669 

29.1243 

29.1818 

29.2393 

29.2969 

29.3546 

29.4123 

102 

29.4700 

29.5278 

29.5857 

29.6436 

29.7016 

29.7596 

29.8177 

29.8759 

29.9341 

29.9924 

103 

30.0507 

30.1091 

30.1675 

30.2260 

30.2845 

30.3432 

30.4018 

30.4695 

30.5193 

30.5781 

104 

30.6370 

30.6960 

30.7550 

30.8140 

30.8732 

30.9323 

30.9916 

31.0508 

31.1102 

31.1696 

105 

31.2290 

31.2886 

31.3481 

31.4077 

31.4674 

31.5272 

31.5870 

31.6468 

31.7067 

31.7667 

106 

31.8267 

31.8868 

31.9469 

32.0071 

32.0674 

32.1277 

32.1880 

32.2485 

32.3089 

32.3695 

107 

32.4301 

32.4907 

32.5514 

32.6122 

32.6730 

32.7338 

32.7948 

32.855S 

32.9168 

32.9779 

108 

33.0391 

33.1003 

33.1615 

33.2229 

33.2842 

33.3457 

33.4072 

33.4687 

33.5303 

33.5920 

109 

33.6537 

33.7155 

33.7773 

33.8392 

33.9012 

33.9632 

3  i.  0252 

34.0874 

34.1495 

34.2118 

110 

34.2741 

34.3364 

34.3988 

34.4613 

34.5238 

34.5863 

34.6490 

34.7117 

34.7744 

34.8372 

111 

34.9001 

34.9630 

35.0259 

35.0890 

35.1520 

35.2152 

35.2784 

35.3416 

35.4049 

35.4683 

112 

35.5317 

35.5952 

35.6587 

35.7223 

35.7860 

35.8497 

35.9134 

35.9772 

36.0411 

36.1051 

113 

36.1690 

36.2331 

36.2972 

36.3613 

36.4256 

36.4898 

36.5542 

36.6185 

36.6830 

36.7475 

114 

36.8120 

36.8766 

36.9413 

37.0030 

37.0708 

37.1357 

37.2006 

37.2655 

37.3305 

27.3956 

115 

37.4607 

37.5259 

37.5911 

37.6564 

37.7217 

37.7871 

37.8526 

37.9181 

37.9837 

38.0493 

116 

38.1150 

38.1808 

38.2466 

38.3124 

38.3783 

38.4413 

38.5103 

38.5764 

38.6426 

38.7088 

117 

38.7750 

38.8413 

38.9077 

38.9741 

39.0406 

39.1071 

39.1737 

39.2404 

39.3071 

39.3738 

118 

39.4407 

39.5075 

39.5745 

39.6415 

39.7085 

39.7756 

39.8428 

39.9100 

39.9773 

40.0146 

119 

40.1120 

40.1791 

40.2469 

40.3145 

40.3821 

40.4498 

40.5175 

40.5853 

40.6531 

40.7210 

120 

40.7890 

40.8570 

40.9250 

40.9932 

41.0613 

41.1296 

41.1979 

41.2662 

41.3346 

41.4031 

121 

41.4716 

41.5402 

41.6088 

41.6775 

41.7463 

41.8151 

41.8839 

41.9528 

42.0218 

42.0908 

122 

42.1599 

42.2291 

42.2983 

42.3675 

42.4368 

42.5062 

42.5756 

42.6451 

42.7147 

42.7843 

123 

42.8539 

42.9236 

42.9934 

43.0532 

43.1331 

43.2030 

43.2730 

43.3131 

43.4132 

43.4833 

124 

43.5536 

43.623? 

43.6942 

43.7646 

43.8350 

43.9055 

43.9761 

44.0467 

44.1173 

14.1881 

125 

44.2589 

44.3297 

44.4006 

44.4716 

44.5426 

44.6136 

44.6848 

44.7560 

44.8272 

44.8985 

126 

44.9693 

45.0412 

45.1127 

45.1842 

45.2558 

45.3275 

15.3991 

45.4709 

45.5427 

45.6146 

127 

45.6865 

45.7585 

45.8305 

45.9026 

45.9747 

46.0469 

46.1192 

46.1915 

46.2639 

46.3363 

128 

46.4088 

46.4813 

46.5539 

46.6266 

46.6993 

46.7721 

46.8449 

46.9178 

46.9907 

47.0637 

129 

47.1368 

47.2099 

47.2830 

47.3563 

47.4295 

47.5029 

47.5763 

47.6497 

47.7232 

47.7968 

130 

47.8704 

47.9441 

48.0178 

48.0916 

48.1654 

48.2392 

48.3133 

48.3873 

48.46H 

18.5355 

131 

48.6097 

48.6839 

48.7582 

48.8326 

48.9070 

48.9815 

49.0560 

49.1306 

49.2052 

49.2799 

132 

49.3547 

49.4295 

49.5043 

49.5793 

49.6542 

49.7293 

49.8014 

49.8795 

49.9547 

50.0300 

133 

50.1053 

50.1807 

50.2561 

50.3316 

50.4071 

50.4827 

50.5584 

50.0341 

50.7099 

50.7857 

134 

50.8616 

50.9375 

50.0135 

51.0896 

51.1657 

51.2419 

51.3181 

51.3944 

51.4707 

51.5471 

135 

51.6235 

51.7001 

51.7766 

51.8532 

51.9299 

52.0067 

52.0834 

52.1003 

52.2372 

52.3142 

136 

52.3912 

52.4682 

52.5454 

52.6226 

52.6998 

52.7771 

52.8545 

52.9319 

53.0094 

53.0869 

137 

53.1645 

53.2421 

53.3198 

53.3976 

53.4754 

53.5532 

53.6312 

53.7091 

53.7872 

53.8653 

138 

53.9434 

54.0216 

54.0999 

54.1782 

54.2566 

54.3350 

54.4135 

54.4921 

54.5707 

54.6493 

139 

54.7280 

54.8068 

54.8856 

54.9645 

54.0435 

55.1225 

55.2015 

55.2807 

55.'359^ 

55.4390 

140 

55.5183 

55.5977 

55.6771 

55.7565 

55.8360 

55.9156 

55.9952 

56.0749 

56.1546 

56.2344 

141 

56.3143 

56.3942 

56.4742 

56.5542 

56.6343 

56.7144 

56.7946 

56.8748 

56.9551 

57.0355 

142 

57.1159 

57.1964 

57.2769 

57.3575 

57.4381 

57.5188 

57.5996 

57.6804 

57.7613 

57.8422 

143 

57.9232 

58.0042 

58.0853 

58.1065 

58.2477 

58.3290 

58.4103 

58.4917 

58.5731 

58.6546 

144 

58.7361 

58.8177 

58.8994 

58.9811 

58.0629 

59.1447 

59.2286 

59.3086 

59.3905 

59.4726 

145 

59.5547 

59.6369 

59.7191 

59.8014 

59.8838 

59.9662 

60.0486 

60.1311 

60.2137 

60.2963 

146 

60.3790 

60.4618 

60.5446 

60.6274 

60.7103 

60.7933 

60.8763 

60.9594 

60.0425 

61.1257 

147 

61  .2090 

61.2923 

61.3756 

61.4591 

61.5425 

61.6261 

61.7097 

61.7933 

61.8770 

01.9608 

148 

62.0446 

62.1284 

62.2124 

62.2964 

62.3804 

62.4615 

62.5487 

62.6329 

62.7171 

62.8015 

149 

62.8858 

62.9703 

63.0548 

63.1393 

63.2239 

63.3086 

63.3933 

63.4781 

63.5629 

63.6478 

150 

63.7328 

63.8178 

63.9029 

63.9880 

64.0731 

64.1584 

64.2437 

64.3290 

64.4144 

64.4999 

151 

64.5854 

64.6710 

64.7566 

64.8423 

64.9280 

65.0138 

65.0997 

65.1856 

65.2716 

85.3576 

152 

65.4437 

65.5298 

65.6160 

65.7022 

65.7886 

65.8749 

65.9613 

65.0478 

66.1344 

66.2209 

153 

66.3076 

66.3943 

66.4811 

66.5679 

66.6548 

66.7417 

66.8287 

66.9157 

67.002S 

07.0900 

154 

67.1772 

67.2645 

67.3518 

67.4392 

67.5266 

67.6141 

67.7017 

67.7893 

67.8770 

67.9617 

155 

68.0525 

68.1403 

68.2282 

68.3161 

68.4041 

68.4922 

68.5803 

68.6685 

68.7567 

68.8450 

MATHEMATICAL  TABLES. 


363 


AREAS   OF  CIRCLES  IN   IMPERIAL   GALLONS   FROM   DIAMETERS— Continued. 


Diam. 

in  Ins 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

156 

68.9334 

69.021S 

69.1103 

69.1988 

69.2873 

69.3760 

69.4647 

69.5534 

69.6422 

69.7311 

157 

69.8200 

69.9090 

69.9980 

70.0871 

70.1762 

70.2654 

70.3547 

70.4440 

70.5333 

70.6228 

158 

70.7122 

70.8018 

70.8914 

70.9810 

71.0707 

71.1605 

71.2503 

71.3402 

71.4301 

71.5201 

159 

71.6102 

71.7003 

71.7904 

71.8805 

71.9709 

72.0613 

72.1516 

72.2421 

72.3326 

72.4231 

160 

72.5138 

72.6044 

72.6952 

72.7859 

72.8768 

72.9677 

73.0586 

73.1496 

73.2407 

73.3318 

161 

73.4230 

73.5142 

73.6055 

73.6969 

73.7883 

73.8798 

73.9713 

74.0629 

74.1515 

74.2462 

162 

74.3379 

74.4297 

74.5216 

74.6135 

74.7055 

74.7975 

74.8896 

74.9817 

75.0739 

75.1662 

163 

75.2585 

75.3509 

75.4433 

75.5358 

75.6283 

75.7209 

75.8136 

75.9063 

75.9991 

76.0919 

164 

76.1848 

76.2777 

76.3707 

76.4637 

76.5569 

76.6500 

76.7432 

76.8365 

76.929^ 

77.0232 

165 

77.1167 

77.2102 

77.3037 

77.3974 

77.4910 

77.5848 

77.6786 

77.7724 

77.8663 

77.9603 

166 

78.0543 

78.1483 

78.2425 

78.3366 

78.4309 

78.5252 

78.6195 

78.7139 

78.8084 

78.9029 

167 

78.9975 

79.0921 

79.1868 

79.2816 

79.3764 

79.4713 

79.5662 

79.6612 

79.7562 

79.8513 

16^ 

79.9464 

80.0416 

80.1369 

80.2322 

80.3276 

80.4230 

80.5185 

80.6140 

80.7096 

80.8053 

169 

80.9010 

80.9988 

81.0926 

81.1885 

81.2844 

81.3804 

81.4765 

81.5726 

81.6687 

81.7650 

170 

81.8612 

81.9576 

82.0540 

82.1501 

82.2469 

82.3435 

82.4401 

82.5368 

82.6335 

82.7303 

171 

82.827) 

82.9240 

83.0210 

83.1180 

83.2151 

83.3122 

83.4094 

83.5067 

83.6039 

83.7013 

172 

83.7987 

83.8962 

83.9937 

84.0913 

84.1889 

84.2866 

84.3844 

84.4822 

84.5801 

84.6780 

173 

84.7760 

84.8740 

84.9721 

85.0702 

85.1684 

85.2667 

85.3650 

85.4634 

85.5618 

85.6603 

174 

85.7589 

85.8575 

85.9561 

86.0548 

86.1536 

86.2524 

86.3513 

86.4503 

86.549? 

86.6483 

175 

86.7474 

86.8466 

86.9458 

87.0451 

87.1444 

87.2438 

87.3433 

87.4428 

S7.5424 

87.6420 

'176 

87.7417 

87.8414 

87.9412 

88.0410 

88.1409 

88.2409 

88.3409 

88.4410 

88.5411 

88.6413 

177 

88.7416 

88.8419 

88.9422 

89.0426 

89.1431 

89.2436 

89.3442 

89.4449 

89.5455 

89.6463 

178 

89.7471 

89.8480 

89.9489 

90.0499 

90.1509 

90.2520 

90.3532 

90.4544 

90.5556 

90.6570 

179 

90.7583 

90.8593 

90.9613 

91.0628 

91.1644 

91.2661 

91.3678 

91.4696 

91.5714 

91.6733 

180 

91.7752 

91.8772 

91.9793 

92.0814 

92.1836 

92.2858 

92.3881 

92.4904 

92.5928 

92.6953 

181 

92.7978 

92.9001 

93.0030 

93.1057 

93.2084 

93.3112 

93.4140 

93.5170 

93.6199 

93.7229 

182 

93.8260 

93.9292 

94.0323 

94.1356 

94.2389 

94.3423 

94.4457 

94.5491 

94.6527 

94.7563 

183 

P4.8599 

94.9636 

95.0674 

95.1712 

95.2750 

95.3790 

95.4830 

95.5870 

95.6911 

95.7952 

184 

95.8995 

96.0037 

96.1080 

96.2124 

96.3169 

96.4214 

P6.5259 

96.6305 

96.7352 

96.8399 

185 

96.9447 

97.0495 

97.1544 

97.2593 

97.3644 

97.4694 

97.5745 

97.6797 

97.7849 

97.8902 

186 

97.9956 

98.1010 

98.2064 

98.3119 

98.4175 

98.523! 

98.6288 

98.7345 

98.8403 

98.9462 

187 

99.0521 

99.1581 

99.2641 

99.3702 

99.4763 

99.5825 

99.6888 

99.7951 

99.9014 

100.0078 

188 

100.1143 

100.2209 

100.3274 

100.4341 

100.5403 

100.6476 

100.7544 

100.8612 

100.9682 

101.0752 

189 

101.1822 

101.2893 

101.3965 

101.5037 

101.6109 

101.7183 

101.8256 

101.9331 

102.0406 

102.1481 

190 

102.2557 

102.3634 

102.4711 

102.5789 

102.6868 

102.7946 

102.9026 

103.0106 

103.1187 

103.2268 

191 

103.3350 

103.4432 

103.  551  5 

103.6598 

103.7682 

103.8767 

103.9852 

104.0938 

104.2024 

104.3111 

192 

104.4198 

104.5?86 

104.6375 

104.7464 

104.8554 

104.9644 

105.0735 

105.1826 

105.2918 

105.401  1 

193 

105.5104 

105.6197 

105.7292 

105.8386 

105.9482 

106.0578 

106.1674 

106.2771 

106.3869 

106.49P7 

194 

106.6066 

106.7  165 

106.8265 

106.9365 

107.046P, 

107.1568 

107.2670 

107.3773 

107.4876 

107.5980 

195 

107.7084 

107.8189 

107.9294 

108.0401 

108.1508 

108.2615 

108.3723 

198.4831 

108.5940 

108.7050 

190 

108.8160 

108.9270 

109.0382 

109.1493 

109.2606 

109.3719 

109.4832 

109.5946 

109.7061 

109.8176 

197 

109.9292 

110.040S 

110.1525 

110.2642 

110.3760 

110.4879 

110.5998 

110.7118 

1  10.8238 

110.9359 

198 

111.0480 

111.1602 

111.2725 

111.3848 

111.4972 

111.6096 

111.7221 

111.8346 

111.9472 

112.0599 

199 

112.1726 

112.2853 

112.3982 

112.5110 

112.6240 

112.7370 

112.8500 

112.9631 

113.0763 

113.1895 

200 

113.3028 

113.4161 

113.5295 

113.6429 

113.7564 

113.'8700 

113.9836 

114.0973 

114.2110 

114.3248 

364 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE  SHOWING  THE  AREAS  OF  SEMI-  SQUARES  IN  IMPERIAL  GALLONS 
CORRESPONDING  TO  SIDES   IN  IMPERIAL  INCHES. 

This  table  shows  the  number  of  gallons  contained  in  a  prism  haying  the  semi-square 
described  on  the  side  as  base,  and  a  height  of  one  inch.  It  is  of  use  in  finding  the  area  in 
gallons  of  a  rectangle.  The  area  is  aXb,  a  and  b  being  the  sides  of  the  rectangle.  But 


=+~ 


"Rules.  —  Add  the  area  of  the  semi-square  on  the  longer  side  of  the  rectangle  to  the  area 
of  the  semi-square  on  the  shorter  side,  and  from  the  sum  deduct  the  semi-square  on  a  line 
equal  to  the  difference  between  the  two  sides,  dimensions  being  in  inches. 


Sides 
in  Ins. 

0 

1 
.00002 

2 
.00007 

3 
.00016 

4 

.00029 

5 
1.00045 

6 
.00065 

7 
.00088 

8 
.00115 

9 
.00146 

1 

.0018 

.0022 

.0026 

.0030 

.003.0 

.0041 

.0046 

.0052 

.0058 

.0065 

2 

.0072 

.OOSO 

.0087 

.0095 

.0101 

.0113 

.0122 

.0131 

.0141 

.0152 

3 

.0162 

.0173 

.0185 

.0196 

.0203 

.0221 

.0234 

.0247 

.0260 

.0274 

4 

.0289 

.0303 

.0318 

.0333 

.0349 

.0365 

.0382 

.0398 

.0415 

.0433 

5 

.0451 

.0469 

.0488 

.0507 

.0526 

.0545 

.0566 

.0586 

.0607 

.0628 

6 

.0649 

.0671 

.0693 

.071fl 

.7390 

.0762 

.0786 

.0809 

.0834 

.0859 

7 

.0884 

.0909 

.0935 

.0961 

.0987 

.1014 

.1042 

.1009 

.1097 

.1125 

8 

.1154 

.1183 

.1213 

.1242 

.1272 

.130?. 

.1334 

.1265 

.1396 

.1428 

9 

.1461 

.1493 

.1526 

.1560 

.1593 

.1627 

.1662 

.1697 

.1732 

.1767 

10 

.1803 

.1840 

.1876 

.1913 

.1950 

.1988 

.2026 

.2065 

.2103 

.2142 

11 

.2182 

.2222 

.2262 

.2303 

.2344 

.2385 

.242P 

.2468 

.2511 

.255* 

12 

.2597 

.2640 

.2684 

.2728 

.2773 

.2818 

.2863 

.2908 

.2954 

.3001 

13 

.3048 

.3095 

.3142 

.3190 

.3238 

.3286 

.3335 

.3385 

.3434 

.3484 

14 

.3534 

.3585 

.3636 

.3688 

.3739 

.3791 

.3844 

.3897 

.3950 

.4003 

15 

.4057 

.4112 

.4166 

.4221 

.4277 

.4332 

.4388 

.4445 

.4502 

.4559 

16 

.4616 

.4674 

.4733 

.4791 

.4850 

.4909 

.4969 

.5029 

.5090 

.5150 

17 

.5211 

.5273 

.5335 

.5297 

.5460 

.5523 

.5586 

.5649 

.5713 

.5778 

18 

.5843 

.5908 

.5973 

.6039 

.6105 

.6172 

.6239 

.6306 

.6373 

.6441 

19 

.6510 

.6579 

.6648 

.1)717 

.6787 

.685? 

.6927 

.6998 

.7070 

.7141 

20 

.7213 

.7285 

.7358 

.7431 

.7504 

.7578 

.7652 

.7727 

.7802 

.7877 

21 

.7952 

.8028 

.8105 

.8181 

.8258 

.8336 

.8413 

.8491 

.8570 

.8649 

22 

.8728 

.8807 

.8887 

.8967 

.9048 

.9129 

.9210 

.9292 

.9374 

.9457 

23 

.9539 

.9622 

.9706 

.9790 

.9874 

.9959 

.0043 

1.0129 

1.0214 

1.0300 

24 

1.0387 

1.0474 

1.0561 

1  .0648 

1.0736 

.0824 

.0913 

1.1002 

1.1091 

1.1180 

25 

1.1270 

1.1361 

.1451 

1.1543 

1.1634 

.1720 

.1818 

1.1910 

1.2003 

1.2097 

26 

1.2190 

.2284 

'  .2378 

1.2473 

1.2568 

.2663 

.2759 

1.2855 

1.2952 

1  .3049 

27 

1.3146 

.3243 

.3341 

1.3440 

1  .3538 

1.3637 

.3737 

1.3836 

1.3936 

1.4037 

28 

1.4138 

.4239 

.4340 

1.4442 

1  .4544 

1.4647 

.4750 

1.4853 

1.4957 

1  .5061 

29 

1.5166 

.5270 

.5375 

1.5481 

1.5587 

.5693 

.5800 

1.5906 

1.6014 

1.6121 

30 

1.6229 

.6338 

.6447 

1.6556 

1.6665 

1.6775 

1.6885 

1.6996 

1.7107 

1.7218 

31 

1.7329 

7441 

1.7554 

1.7666 

1.7780 

1.7893 

.8007 

1.8121 

1.8235 

1  .8350 

32 

1.8465 

.8581 

1  .8697 

1.8813 

1.8930 

1.9047 

.9164 

1  .9282 

1.9400 

1.9519 

33 

1.9638 

.9757 

1.9876 

1.9996 

2.0117 

2.0237 

2.0358 

2.0480 

2.0601 

2.0723 

34 

2.0846 

2.0969 

2.1092 

2.1215 

2.1339 

2.1463 

2.1588 

2.1713 

2.1838 

2.1964 

35 

2.2090 

2.2216 

2.2343 

2.2470 

2.2598 

2.2726 

2.2854 

2.2983 

2.3111 

2,3241 

30 

2.3370 

2.3500 

2.3631 

2.3762 

2.3893 

2.4024 

2.4156 

2.4288 

2.4421 

2.4554 

37 

2.4687 

2.4820 

2.4954 

25089 

2.5223 

2.5358 

2.5494 

2.5630 

2.5766 

2.5902 

38 

2.6039 

2.6176 

2.6314 

2.6452 

2.6590 

2.6729 

2.6868 

2.7007 

2.7147 

2.7287 

39 

2.7428 

2.7569 

2.7710 

2.7851 

2.7993 

2.8136 

2.8278 

2.8121 

2.8565 

2.8708 

40 

2.8852 

2.8997 

2.9142 

2.9287 

2.9432 

2.9578 

2.9724 

2.9871 

3.0018 

3.0165 

41 

3.0313 

3.0461 

3.0609 

3.0758 

3.0907 

3.1057 

3.1207 

3.1357 

3.1507 

3.1658 

42 

3.1810 

3.1961 

3.2113 

3.2266 

3.2418 

3.2572 

3.2725 

3.2879 

3.3033 

3.3188 

43 

3.3342 

3.349S 

3.3653 

3.3809 

3.3966 

3.4122 

3.4279 

3.4437 

3.4595 

3.4753 

44 

3.4911 

3.5070 

3.5229 

3.5389 

3.5549 

3.5709 

3.5870 

3.6031 

8.6192 

3  6354 

45 

3.651P 

3.6679 

3.6842 

3.7005 

3.7168 

3.7332 

3.7496 

3.7661 

3.7826 

3.7991 

MATHEMATICAL  TABLES. 


365 


AREAS    OF    SEMI-SQUARES    IN    IMPERIAL    GALLONS—  Continued. 


Sides  in  Ins. 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

16 

3.8157 

3.8323 

3.8490 

3.8657 

3.8824 

3.8991 

3.9159 

3.9327 

3.9496 

3.9665 

47 

3.9834 

.40004 

4.0174 

4.0344 

4.0515 

4.0686 

4.0858 

4.1030 

4.1202 

4.1374 

48 

4.1547 

4.1721 

4.1894 

4.2068 

4.2243 

4.2417 

4.2593 

4.2768 

4.2944 

4.3120 

49 

4.3297 

4.3473 

4.3651 

4.3828 

4.4006 

4.4185 

4.4363 

4.4542 

4.4722 

4.4902 

50 

4.5082 

4.5262 

4.5443 

4.5624 

4.5806 

4.5988 

4.6170 

4.6353 

4.6536 

4.6719 

51 

4.6903 

4.7087 

4.7272 

4.7456 

2.7642 

4.7827 

4.8013 

4.8199 

4.8386 

4.8573 

52 

4.8760 

4.8948 

4.9136 

4.9325 

4.9513 

4.9703 

4.9892 

5.0082 

5.0272 

5.0463 

53 

5.0651 

5.0845 

5.1037 

5.1229 

5.1421 

5.1614 

5.1807 

5.2001 

5.2195 

5.2389 

54 

5.2583 

5.2778 

5.2974 

5.3169 

5.3365 

5.3562 

5.3758 

5.3955 

5.4153 

5.4351 

55 

5.4549 

5.4747 

5.4946 

5.5146 

5.5345 

5.5545 

5.5746 

5.594C 

5.6147 

5.6349 

56 

5.6551 

5.6753 

5.6955 

5.7158 

5.7361 

5.7565 

5.7769 

5.7973 

5.8178 

5.8383 

57 

5.8588 

5.8794 

5.9000 

5.9207 

5.9413 

5.9621 

5.9828 

6.0036 

6.0244 

6.0453 

58 

6.0662 

6.0871 

6.10S1 

6.1291 

6.1502 

6.1712 

6.1924 

6.2135 

6.2347 

6.2559 

59 

6.2772 

6.2985 

6.3198 

6.3412 

6.3626 

6.3840 

6.4055 

6.4270 

6.4486 

6.4702 

60 

6.4918 

6.5134 

6.5351 

6.5569 

6.5786 

6.6004 

6.6223 

6.6441 

6.6660 

6.6880 

61 

6.7100 

6.7320 

6.7540 

6.7761 

6.7983 

6.8204 

6.8426 

6.8649 

6.8871 

6.9094 

62 

6.9318 

6.9542 

6.9766 

6.9990 

7.0215 

7.0440 

7.0666 

7.0892 

7.1118 

7.1345 

63 

7.1572 

7.1799 

7.2027 

7.2255 

7.2484 

7.2712 

7.2942 

7.3171 

7.3401 

7.3631 

64 

7.3862 

7.4093 

7.4324 

7.4556 

7.4788 

7.5021 

7.5253 

7.5487 

7.5720 

7.5954 

65 

7.6188 

7.6423 

6.6658 

7.6893 

7.7129 

7.7365 

7.7601 

7.7838 

7.8075 

7.8313 

66 

7.8550 

7.8789 

7.9027 

7.9266 

7.9505 

7.9745 

7.9985 

8.0226 

8.0466 

8.0707 

67 

8.0949 

8.1191 

8.1433 

8.1675 

8.1918 

8.2162 

8.2405 

8.2649 

8.2893 

8.3138 

68 

8.3383 

8.3629 

8.3874 

8.4121 

8.4367 

8.4614 

8.4861 

8.5109 

8.5357 

8.5605 

69 

8.5854 

8.6103 

8.6352 

8.6602 

8.6852 

8.7102 

8.7353 

8.7604 

8.7856 

8.8108 

70 

8.8360 

8.8613 

8.8866 

8.9119 

8.9373 

8.9627 

8.9881 

9.0136 

9.0391 

9.0647 

71 

9.0903 

9.1159 

9.1416 

9.1673 

9.1930 

9.2188 

9.2446 

9.2704 

9.2963 

9.3222 

72 

9.3482 

9.3741 

9.4002 

9.4262 

9.4523 

9.4784 

9.5046 

9.5308 

9.5570 

9.5833 

73 

9.6096 

9.6360 

9.6624 

9.6888 

9.7152 

9.7417 

9.7682 

9.7948 

9.8214 

9.8480 

74 

9.8747 

9.9014 

9.9282 

9.9549 

9.9818 

10.0086 

10.0355 

10.0624 

10.0894 

10.1164 

75 

10.1434 

10.1705 

10.1976 

10.2247 

10.2519 

10.2791 

10.3063 

10.3336 

10.3609 

10.3883 

76 

10.4157 

10.4431 

10.4706 

10.4981 

10.5256 

10.5532 

10.5808 

10.6084 

10.6361 

10.6638 

77 

10.6916 

10.7194 

10.7472 

10.7751 

10.8030 

10.8309 

10.8589 

10.8869 

10.9149 

10.9430 

78 

10.9711 

10.9992 

11.0274 

11.0557 

11.0839 

11.1122 

11.1405 

11.1689 

11.1973 

11.2257 

79 

11.2542 

11.2827 

11.3113 

11.3398 

11.3685 

11.3971 

11.4258 

11.4545 

11.4833 

11.5121 

80 

11.5409 

11.5698 

11.5987 

11.6276 

11.6566 

11.6856 

11.7147 

11.7438 

11.7729 

11.8021 

81 

11.8313 

11.8605 

11.8898 

11.9191 

11.9484 

11.9778 

12.0072 

12.0366 

12.0661 

12.0956 

82 

12.1252 

12.1548 

12.1844 

12.2141 

12.2438 

12.2735 

12.3033 

12.3331 

12.3629 

12.3928 

83 

12.1227 

12.4527 

12.4827 

12.5127 

12.5428 

12.57?9 

12.6030 

12.6332 

12.6634 

12.6936 

84 

12.7239 

12.7542 

12.7845 

12.8149 

12.8453 

12.8758 

12.9063 

12.9368 

12.9674 

12.9980 

85 

13.0286 

13.0593 

13.0900 

13.1208 

13.1515 

13.1824 

13.2132 

13.2441 

13.2750 

13.3060 

86 

13.3370 

13.3680 

13.3991 

13.4302 

13.4613 

13.4925 

13.5237 

13.555C 

13.5863 

13.6176 

87 

13.6490 

13.6803 

13.7118 

13.7432 

13.7747 

13.8063 

13.8379 

13.8695 

13.9011 

13.9328 

88 

13.9645 

13.9963 

14.0281 

14.0599 

14.0918 

14.1237 

14.1556 

14.187C 

14.2196 

14.2516 

89 

14.2837 

14.315S 

14.3480 

14.380:> 

14.4124 

14.4446 

14.4769 

14.509? 

14.5416 

14.5740 

90 

14.6065 

14.6390 

14.6715 

14.7040 

14.7366 

14.7692 

14.8019 

14.8346 

14.8673 

14.9001 

91 

14.9329 

14.9657 

14.9986 

15.0315 

15.0644 

15.0974 

15.1304 

15.1635 

15.1966 

15.2297 

92 

15.2629 

15.2961 

15.3293 

15.3626 

15.3959 

15.4292 

15.4626 

15.4960 

15.5295 

15.5630 

93 

15.5965 

15.6300 

15.6636 

15.6973 

15.7309 

15.7646 

15.7984 

15.8322 

15.8660 

15.8998 

94 

15.9337 

15.9676 

16.0016 

16.0356 

16.0696 

16.1037 

16.1378 

16.1719 

16.2061 

16.2403 

95 

16.2745 

16.3088 

16.3431 

16.3775 

16.4119 

16.4463 

16.4807 

16.5152 

16.5498 

16.5843 

96 

16.6189 

16.6536 

16.6883 

16.7230 

16.7577 

16.7925 

16.8273 

16.8622 

16.8971 

16.9320 

97 

16.9670 

17.0020 

17.0370 

17.0721 

17.1072 

17.1423 

17.1775 

17.2127 

17.2480 

17.2833 

98 

17.3186 

17.3540 

17.389* 

17.4248 

17.4603 

17.4958 

17.5313 

17.5669 

17.6025 

17.6382 

99 

17.6739 

17.7096 

17.7453 

17.7811 

17.8170 

17.8528 

17.8887 

17.9247 

17.9606 

17.9967 

100 

18.0327 

18.0688 

18.1049 

18.1411 

18.1773 

18.2135 

18.2497 

18.2860 

18.3224 

18.3588 

366 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


AREAS    OF    SEMI-SQUARES    IN    IMPERIAL    GALLONS— Continued. 


Sides  in  Ins. 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

101 

18.3952 

18  4316 

18.4681 

18.5046 

18.5412 

18.5777 

18.6144 

IS.  65  1C 

18.6877 

18.7245 

102 

18.7612 

18.7980 

18.8349 

18.8717 

18.9087 

18.9456 

18.9826 

19.0191 

19.0567 

19."93S 

103 

19.1309 

19.1681 

19.2053 

19.2425 

19.2798 

19.3171 

19.3544 

19.3918 

19.4292 

19.466/ 

104 

19.5042 

19.5417 

19.5793 

19.6169 

19.6545 

19.6922 

19.7299 

19.7676 

19.8054 

19.8432 

105 

19.8811 

19.9189 

19.9569 

19.9948 

20.0328 

20.0709 

20.1089 

20.1470 

20.1852 

20.  2233 

106 

20.2615 

30.2998 

20.3381 

20.3764 

20.414S 

20.1531 

20.4916 

20.5300 

20.5685 

20.6071 

107 

20.6456 

20.684.? 

20.7229 

20.7616 

20.8003 

20.8390 

20.8778 

20.9167 

20.9555  20.9944 

108 

21.0333 

21.0723 

21.1113 

21.1504 

21.1894 

21.2286 

21.2677 

21.3069 

21.3461 

21.3  54 

109 

21.4247 

21.4640 

21.5034 

21.5428 

21.5^22 

21.6217 

21.6012 

21  .7007 

21.7403 

21.7799 

110 

21.8195 

21.8593 

21.8990 

21.9388 

21.9785 

22.0184 

22.0583 

22  .0981 

22.1381 

22.1781 

111 

22.2181 

22.2581 

22.2982 

22.3384 

22.3785 

22.4187 

22.4589 

22.499i 

22.5395 

22.5793 

112 

22.6202 

22.6606 

22.7011 

22.7416 

22.7821 

22.8226 

22.8632 

22.9039 

22.9445 

22.9852 

113 

23.0260 

23.0667 

23.1075 

23.1484 

23.1893 

23.2302 

23.2711 

23.3121 

23.3531 

23..3942 

114 

23.4353 

23.4764 

23.5176 

23.5588 

23.6000 

23.6413 

23.6826 

23.7240 

23.7654 

23.  £008 

115 

23.8483 

23.8897 

23.9313 

23.9728 

24.0144 

24.0561 

24.0978 

24.1395 

24.1812 

24.2230 

116 

24.2648 

24.3067 

24.3486 

24.3905 

24.4324 

24.4744 

24.5165 

24.5585 

24.6006 

24.6428 

117 

24.6850 

24.7272 

24.7694 

24.8117 

24.8540 

24.8964 

24.9388 

24.9812 

25.0237 

25.0662 

118 

25.1087 

25.1513 

25.1939 

25.2386 

25.2793 

25.3220 

25.3647 

25.407i 

25.4503 

25.4932 

119 

25.5361 

25.5790 

25.6220 

25.6650 

25.7081 

25.7512 

25.7943 

25.837; 

25.880o 

25.9238 

120 

25.9671 

26.0104 

26.0537 

26.0971 

26.1405 

26.1839 

26.2274 

26.270S 

20.3145 

26.3581 

121 

26.4017 

26.4453 

26.4890 

26.5328 

20.5765 

26.6203 

26.6542 

26.708f 

2G.751P 

26.7959 

122 

26.8399 

26.8839 

26.9279 

26.9720 

27.0162 

27.0603 

27.1045 

27.148* 

27.1931 

27.2373 

123 

27.2817 

27.3201 

27.3705 

27.4149 

27.4594 

27.5089 

27.5485 

27.5931 

27.6377 

27.6824 

124 

27.7271 

27.7718 

27.8166 

27.8614 

27.9063 

27.9511 

27.9961 

28.04K 

28.0860 

28.1310 

125 

28.1761 

28.2212 

28.2663 

28.3115 

28.3567 

28.4020 

28.4472 

28.492( 

28.5379 

28.5833 

126 

28.6287 

28.6742 

28.7197 

28.7652 

28.8108 

28.8564 

28.9020 

28.9477 

28.9934 

28.0392 

127 

29.0849 

29.1303 

29.1766 

29.2225 

29.2684 

29.3144 

29.3C04 

29.406.r 

29.4525 

29.4986 

128 

29.5448 

29.5910 

29.6372 

29  6834 

29.7297 

29.7761 

J9.8224 

29.868; 

29.9152 

29.9017 

129 

30.0082 

30.0548 

30.1013 

30.1480 

30.194C 

30.2413 

30.2880 

30.334,' 

30.3816 

30.4284 

130 

30.4753 

30.5222 

30.5691 

30.6161 

30.6631 

30.7101 

30.7572 

30.^,04; 

30.8515 

30.8987 

131 

30.9459 

30.9932 

31.0405 

31.0878 

31.1352 

31.1«2fi 

31.2300 

31.277£ 

31.3250 

31.3726 

132 

31.4202 

31.4678 

31.5155 

31.5631! 

31.0109 

31.65S7 

31.7005 

31.7545 

31.8022 

31.8501 

133 

31.8981 

31.9460 

31.9941 

32.0421 

32.0902 

32.1383 

32.1805 

32.2347 

32.2829 

32.3312 

134 

32.3795 

32.4279 

32.4763 

32.5247 

32.5731 

32.6216 

32.6701 

32.7187 

32.7673 

32.8159 

135 

42.8646 

32.9133 

32.9621 

33.0108 

33.0596 

33.1085 

33.1574 

33.2003 

33.2553 

33.3043 

136 

43.3533 

33.4024 

33.4515 

33.5006 

33.5498 

33.5990 

33.6482 

33.6975 

33.74^)8 

33.7962 

137 

33.8456 

33.8950 

33.9445 

33.9940 

34.0135 

34.0931 

31.1427 

34.1923 

34.2420 

34.2917 

138 

34.3415 

34.3913 

34.4411 

34.4910 

35.5409 

34.5908 

34.6408 

34.6908 

34.7408 

.34.7909 

139 

34.8410 

34.8911 

34.9413 

34.9915 

35.  Oil.S 

35.0921 

35.1424 

35.1928 

35.2432 

35.29.36 

140 

35.3441 

45.3946 

35.4452 

35.4957 

35.5464 

35.597C 

35.6477 

''5.6984 

35.7492 

35.8000 

!41 

35.8508 

35.9017 

35.95?0 

36.0035 

36.0545 

36.1055 

36.1560 

30.2077 

36.2588 

36.3009 

142 

36.3611 

36.4124 

36.4636 

36.5149 

36.5663 

36.6177 

36.6691 

30.7205 

36.7720 

36.8235 

143 

36.8751 

36.9267 

36.9783 

37.0300 

37.0817 

37.1334 

37.1852 

37.2370 

37.2888 

.37.3407 

144 

37.3926 

37.4446 

37.4960 

37.5480 

37.600'] 

37.6527 

37.7049 

37.7570 

37.8092 

37.8615 

145 

37.9138 

37.9661 

38.0184 

38.0708 

38.1232 

38.1757 

38.2282 

38.2807 

38.3.333 

38.3859 

14(5 

38.4385 

38.4912 

3S.5439 

38.5966 

38.0494 

38.7022 

38.7551 

38.8080 

38.8609 

38.9139 

147 

38.9069 

39.0199 

39.0730 

39.1201 

39.1792 

39.2324 

39.2850 

39.3389 

39.3922 

39.4455 

148 

39.4988 

39.5522 

39.6057 

39.0591 

39.7126 

39.7662 

39.8197 

39.8734 

39.9270 

39.9807 

149 

40.0344 

40.0882 

40.1420 

40.1958 

40.24% 

40.3035 

40.3575 

40.4115 

40.4055 

40.5195 

150 

40.5736 

40.6277 

40.6819 

40.7360 

40.7903 

40.8445 

40.8988 

40.9532 

41.0075 

41.0619 

151 

41.1164 

41.1708 

41.2254 

41.2799 

11.3345 

41.3891 

41.4438 

41.4985 

4  1  .5522 

41  .6080 

152 

41.6628 

41.7176 

41.7725 

41.8274 

41.8823 

41.9373 

41.9923 

41.0474 

42  1025 

42.1576 

153 

42.2128 

42.2080 

12.3232 

42.3785 

42.4338 

42.4891 

42.5445 

42.5999 

42.6554 

42.7108 

154 

42.7664 

42.8219 

42.8775 

42.9331 

42.9888 

43.0445 

43.1003 

43.1500 

4.4.2118 

43.2077 

155 

43.3236 

43.3795 

43.4354 

43.4914 

43.5475 

43.6035 

43.6596 

43.7158 

43.7719 

43.8281 

MATHEMATICAL  TABLES. 


367 


AREAS  OF  SEMI-SQUARES  IN  IMPERIAL  GALLONS—CtafMMM*. 


Sides  in  Ins. 

0 

1 

2 

3 

4 

5 

6 

7 

9 

156 
157 
158 
159 
160 

43.8844 
44.4488 
45.0168 
45.5885 
46.1637 

43.9407 
44.5055 
45.0738 
45.6458 
46.2214 

43.9970 
44.5621 
45.1309 
45.7032 
46.2792 

44.0533 

44.6188 
45.1880 
45.7607 
46.3370 

44.1097 
44.6756 
45.2451 
45.8181 
46.3948 

44.1661 
44.7324 
45.3022 
45.8757 
46.4527 

44.2226 
44.7892 
45.3594 
45.9332 
46.5106 

44.2791 
44.8461 
45.4166 
45.9908 
46.5685 

44  3356 
44.9029 
45.4739 
46.0484 
46.6265 

44.3922 
44.9599 
45.5312 
46.1060 
46.6845 

161 
162 
163 
164 
165 

46.7426 
47.325C 
47.9111 
48.5003 
49.0940 

46.8007 
17.3835 
47.9099 
48.5599 
19.153b 

46.8588 
47.4420 
48.0287 
48.6191 
49.2131 

46.9169 
47.5005 
48.0876 
48.6784 
49.2727 

46.9751 
47.5590 
48.1435 
48.7376 
49.3324 

47.0333 
47.6176 
48.2055 
48.7969 
49.3920 

47.0916 
47.6762 
48.2645 
48.8563 
49.4517 

47.1499 
47.7349 
48.3235 
48.9157 
49.5115 

47.2082 
47.7936 
48.3825 
48.9751 
49.5713 

47.2666 
47.8523 
48.4416 
49.0345 
49.6311 

166 
167 
168 
169 
170 

49.6909 
50.2914 
50.8955 
51.5032 
52.1145 

19.7508 
50.3517 
50.9561 
51.5642 
52.1753 

49.8107 
50.4119 
51.0168 
51  .6252 
52.2372 

49.8707 
50.4723 
51.0774 

51.6862 
52.2986 

49.9307 
50.5323 
51.1382 
51.7478 
52.3600 

49.9907 
50.5930 
51.1989 
51.8084 
52.4215 

50.0508 
50.6534 
51.2597 
51.8696 
52.4830 

50.1109 
50.7139 
51.3205 
51.9307 
52.5446 

50.1710 
50.7744 
51.3814 
51.9920 
52.6062 

50.2312 
50.8349 
51.4423 
51.0532 
52.6678 

171 
172 
173 
174 
175 

52.7291 
53.3480 
53.9701 
54.5958 
55.2252 

52.7911 
53.4100 
54.0325 

54.0533 
55.2883 

52.8528 
53.4721 
54.0919 
54.7214 
55.3515 

52.9146 
^3.5342 
54.157-; 
54  7842 
55.4147 

52.9764 
53.5904 
54.2199 
54.8471 
55.4779 

53.0382 
53.6586 
54.2825 
54.9100 
55.5412 

53.1001 
53.7208 
54.3451 
54.9730 
55.6045 

53.1620 
53.7831 
54.4077 
55.0360 
55.6678 

53.2240 
53.8454 
54.4704 
55.0990 
55.7312 

53.2859 
53.9077 
54.5331 
55.1621 
55.7946 

176 
177 
178 
179 
180 

55.8581 
56.4947 
57.1348 
57.7786 
58.4260 

55.9216 
56.5585 
57.1990 
57.8432 
58.4909 

55.9851 
56.6224 
57.2633 
57.9078 

58.5559 

56.0487 
56.6863 
57.3276 
57.9724 
53.6209 

56.1123 
56.7502 
57.3919 
58.0371 

58.6859 

56.1759 
56.8143 
57.4563 
58.1018 
53.7510 

56.2396 
56.8783 
57.5206 
58.1666 
58.8161 

56.3033 
56.9424 
57.5851 
58.2314 
58.8813 

56.3671 
57.0065 
57.6495 
58.2962 
58.9465 

56.4308 
57.0706 
57.7140 
58.3611 
59.0117 

181 
182 
183 
184 
185 

59.0769 
59.7315 
60.3397 
61.0515 
31.7169 

59.1422 
59.7972 
80.4557 
31.1179 
61.7837 

59.2076 
59.8629 
60.5218 
31.1843 
61.8504 

59.2729 
59.9286 
60.5879 
61.250S 
61.9173 

59.3383 
59.9944 
60.6540 
61.3173 
61.9841 

59.4038 
60.0602 
60.7202 
61.3838 
62.0510 

59.4693 
60.1260 
60.7864 
61.4503 
62.1179 

59.5348 
60.1919 
60.8526 
61.5169 
62.1849 

59.6003 
60.2578 
60.9189 
61.5836 
62.2519 

59.6659 
60.3237 
C0.9852 
61  .6502 
62.3189 

186 
187 
188 
189 
190 

62.3859 
33.0536 
63.7318 
64.4146 
85.0931 

62.4530 
83.1230 
63.8023 

64.4328 
65.1638 

32.5202 
63.1935 
33.8705 
84.5510 
55.2352 

62.5874 
63.2611 
63.9384 
34.6193 
65.3038 

62.6546 
63.3286 
64.0063 
64.6870 
65.3724 

62.7218 
63.3962 
64.0743 
64.7559 
65.4411 

62.7891 
63.4639 
64.1423 
64.8243 
65.5099 

62.8564 
63.5315 
64.2103 
64.8927 
65.5786 

62.9238 
63.5993 
64.2784 
64.9311 
65.6474 

62.9911 
63.6670 
64.3465 
65.0296 
35.7162 

191 
192 
193 
194 
195 

65.7851 
66.4753 
67.1700 
C7.8679 
68.5694 

65.8540 
86.5450 
37.2396 
67.9379 
68.6397 

65.9229 
66.6143 
67.3093 
68.0079 
68.7101 

65.9919 
66.6837 
67.3790 
68.0779 
68.7805 

66.060G 
66.7530 
67.4487 
68.1480 
68.8510 

66.1300 

66.8224 
67.5185 
68.2182 
68.9214 

66.1991 
66.8919 
67.5883 
68.2883 
68.9920 

66.2682 
66.9614 
67.6581 
68.3585 
69.0625 

66.3373 
67.0309 
67.7280 
68.4288 
69.1331 

66.4065 
67.1004 
67.7979 
68.4990 
69.2038 

196 
197 
198 
199 
200 

69.2744 
69.9831 
70.6954 
71.4113 
72.1  80S 

69.3451 
70.0542 
70.766S 
71.4831 
72.2030 

69.4159 
70.1253 
70.8383 
71.5549 

72.2752 

69.4867 
70.1964 
70.9098 
71.6268 
72.3474 

69.5575 
70.2676 
70.9813 
71.0987 
72.4196 

69.6283 
70.3388 
71.0529 
71.7706 
72.4919 

69.6992 
70.4101 
71.1245 
71.8426 
72.5C43 

69.7701 
70.4813 
71.1962 
71.9146 
72.6366 

69.8411 
70.5527 
71.2678 
71.9866 
72.7090 

69.9121 
70.6240 
71.3396 
72.0587 
72.7815 

CHAPTER  XXII. 
CONVERSION    FACTORS. 


THE  use  of  metric  units  on  the  continent  of  Europe  for  indus- 
trial and  commercial  purposes,  their  use  in  this  country  in  chemical, 
metallurgical,  and  physical  calculations,  makes  it  often  necessary 
to  convert  our  customary  English  measures  into  metric  units  or 
vice  versa.  The  following  table,  compiled  by  C.  W.  Hunt,  is  very 
useful  in  this  regard: 


Millimeters  X  .03937  =  inches. 
Millimeters  -=-  25.4  =  inches. 
Centimeters  X  .3937  =  inches. 
Centimeters  -*-  2.54  =  inches. 
Meters X 39. 37=  ins.  (Act  Congress). 
Meters  X  3.281  =  feet. 
Meters  X  1 .094  =  yards. 
Kilometers  X  -621  =  miles. 
Kilometers  -~  1.6093  =  miles. 
Kilometers  X  3280.8693  =  feet. 
Square  millimetersX.00155  =  sq.  ins. 
Square  millimeters  ~-  645.  l  =  sq.  ins. 
Square  centimeters  X  .155  =  sq.  inches. 
Square  centimeters  -f-  6. 451  =sq.  ins. 
Square  meters  X  10.764  =  square  feet. 
Square  kilometers  X  247. 1  =  acres. 
Hectare  X  2.47 1  =  acres. 
Cu.  centimeters -f- 16. 383  =  cu.  inches. 
Cu.  centimeters  -r-  3.69  =  fluid  drams 

(U.  S.  P.). 

Cu.  cent. -*- 29.57  =  fl.  oz.  (U.  S.  P.). 
Cubic  meters  X  35.3 15  =  cubic  feet. 
Cubic  meters  X 1 .308=  cubic  yards. 
Cubic    meters  X  264.2  =  gallons     (231 

cu.  in.). 

LitersX61.022  =  cu.  in.  (Act  Cong.). 
Liters X 33.84  =  fl.  oz.  (U.  S.  P.). 
Liters  X, 2642  =  gallons  (231  cu.  in.). 
Inters -h3.78=  gallons  (231  cu.  in.). 
Li  ters-f- 28.3 16=  cubic  feet. 
Hectoliters  X  3,531  =  cubic  feet. 


Hectoliters  X  2.84= bushels     (2150.42 

cu.  in.). 

Hectoliters  X .  131  =  cubic  yards. 
Hectoliters -r- 26.42  =  gals.  (231  cu.  in.). 
Grammes  XI 5. 432  =  grains  (Act  Con- 


Grammes -f-  981  =  dynes. 
Grammes  (water)-r-29.57  =  fl.  ounces. 
Grammes  -*•  28.35  =  ounces  avoir. 
Grammes   per   cu.    cent. -7-27.7  =  Ibs. 

per  cu.  in. 

Joule  X  .7373  =  foot-pounds. 
Kilogrammes  X  2.2046  =  pounds. 
Kilogrammes  X  35.3  =  ounces  avoir. 
Kilogms. -=-907.2  =  tons  (2000  Ibs.). 
Kilogms.  per  sq.  cent.X  14. 223  =  Ibs. 

per  square  inch. 

Kilogram-meters  X  7.233  =  f  t.-lbs. 
Kilogms.  per  meter  X  .672  =  Ibs.  per  ft. 
Kilogms.  per  cu.  meter  X  .062  =  Ibs.  per 

cubic  foot. 
Kilogms.  per  chevalX  2.235  =  Ibs.  per 

horse-power. 

Kilowatts  X  1.34= horse-power. 
Watts  -r-  746  =  horse-power. 
Watts X. 7373  =  ft.-lbs.  per  second. 
Calorie  X  3.968  =B.t.u. 
Cheval  vapeur  X  .9863  =  horse-power. 
(Centigrade XI. 8)+ 32  =  deg.  Fahr. 
Franc  X .  193  =  dollars. 
Gravity  Paris =980.94  centimeters  per 

second. 

368 


CONVERSION  FACTORS. 


369 


One  cubic  meter. 


REDUCTION    OF    FRENCH   AND   ENGLISH   MEASURES. 

f 39. 37043  inches 

Onemeter I   3.28087  feet 

( 35. 314  cubic  feet 
I    1 . 308  cubic  yards 

One  cubic  yard 0 . 7645  cubic  meters 

One  cubic  foot 0.02832  cubic  meters 

^          u-     i     •  /  6 1.023  cubic  inches 

One  cubic  decimeter {   Q  Q353  cubic  ^ 

One  cubic  foot 28.32  cubic  decimeters 

One  cubic  centimeter 0.061  cubic  inches 

One  cubic  inch 16.387  cubic  centimeters 

61.023  cubic  inches 
0.03531  cubic  feet 
2. 1135  pints 

1.0567  quarts  (American) 
0 . 2642  gallons  (American) 
2 .202  pounds  of  water  at  62°  F. 

One  cubic  foot 28.317  liters 

One  gallon  (American,  231  cubic  inches). .       3 . 785  liters 
One  gallon  (British,  277.274  cubic  inches) .       4 . 543  liters 

One  quart  (57.75  cubic  inches) 946.30  cubic   centimeters 

One  pint  (28.875  cubic  inches) 473.15  cubic  centimeters 

One  milligramme 0 .015432  grains 

One  grain 64 . 799  milligrammes 

One  gramme 15 . 43235  grains 

One  grain 0 .064799  grammes 

One  gramme 0 .03215  ounces  (troy) 

One  ounce  (troy,  480  grains) 31 . 10348  grammes 


One  liter    (0.001    cubic   meter 
or  one  cubic  decimeter).  .  . . 


Milligrammes 
to 
Grains. 

Grains 
to 
Milligrammes. 

Grammes 
to 
Grains. 

Grains 
to 
Grammes. 

Grammes 
to  Ounces 
(Avoirdupois). 

1 

0.01543 

64.7989 

15.43235 

0.064799 

0.035274 

2 

0.03086 

129.5978 

30.86470 

0.129598 

0.070548 

3 

0.04630 

194.3968 

46.29705 

0.194397 

0.105822 

4 

0.06173 

259.1957 

61.72940 

0.259196 

0.141096 

5 

0.07716 

323.9946 

77.16175 

0.323995 

0.176370 

6 

0.09259 

388.7935 

92.59100 

0.388794 

0.211644 

7 

0.10803 

453.5924 

108.02645 

0.453593 

0.246918 

8 

0.12346 

518.3914 

123.45880 

0.518392 

0.282192 

9 

0.13889 

583.1903 

138.89115 

0.583191 

0.317466 

10 

0.15430 

647.9890 

154.32350 

0.647990 

0.352740 

370 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


One  gramme 0 .035274  ounces  (avoirdupois) 

One   ounce    (avoirdupois,    437.50 

grains) J 28 . 35  grammes 

One  kilogramme 2.2046  pounds  (avoirdupois) 

One  pound     (avoirdupois,     7000 

grains) 0 . 45359  kilogrammes 

One  pound  (troy,  5760  grains).  .  .  0.37324  kilogrammes 


Ounces 
(Avoirdupois) 
to  Grammes. 

Grammes  to 
Ounces 
(Troy). 

Ounces 
(Troy) 
to  Grammes. 

Kilogrammes 
to  Pounds 
(Avoirdupois). 

Pounds 
(Avoirdupois) 
to  Kilogrammes. 

28.3495 

0.03215 

31  .  10348 

2.20462 

0.45359 

56.6991 

0.06430 

62.20696 

4.40924 

0.90719 

85.0486 

0.09645 

93.31044 

6.61386 

1.36078 

113.3981 

0.12860 

124.41392 

8.81849 

1.81437 

141.7476 

0.16075 

155.51740 

11.02311 

2.26796 

170.0972 

0.19290 

186.62089 

13.22773 

2.72156 

198.4467 

0.22505 

217.72437 

15.43235 

3.17515 

226.7962 

0.25721 

248.82785 

17.63697 

3.62874 

255.1457 

0.28936 

279.93133 

19.84159 

4.08233 

283.4950 

0.32150 

311.03480 

22.04620 

4.53590 

EQUIVALENTS    OF   WORK   AND   HEAT. 

1        B.t.u.  =       778  ft.-lbs.    =     17.59  watts. 
42.41      "       =  33000       "        =746  "        =   1 


H.P. 


In  the  French  or  metric  system  of  units,  a  heat-unit  or  calorie 
is  the  quantity  of  heat  required  to  raise  1  kilogramme  of  pure  water 
1°  C.  at  or  about  4°  C. 

The  following  tabular  statement  shows  the  relation  of  the 
French  and  English  units: 

FRENCH   AND   ENGLISH   UNITS   COMPARED. 

1  calorie 3.968  B.t.u. 

0.252  calorie 1 

French  mechanical  equivalent,   425.0    kilogram- 
meters  3075  ft.-lbs. 

107.7  kilogram-meters 1,  or  778  ft.-lbs. 

For  convenience  in  translating  French  and  German  results  into 
English  or  American  we  have  the  following  compound  units: 

EQUIVALENT   COMPOUND   UNITS. 

1  calorie  per  square  meter 0 . 369  B.t.u.  per  square  foot 

1  B.t.u.  or  1  H.u.  per  square  foot.  .  2.713  calories  per  square  meter 

1  calorie  per  kilogramme 1 .800  H.u.  per  pound 

1  H.u.  per  pound ' 0 .556  calorie  per  kilogramme 


CONVERSION   FACTORS. 


371 


CONVERSION    OF    HEAT-UNITS. 


Calories  per 
Kilogramme  to 
British  Thermal 
Units  per  Pound. 

Calories  per 
Cubic  Meter  to 
British  Thermal 
Units  per 
Cubic  Foot. 

British  Thermal 
Units  per  Pound 
to  Calories  per 
•  Kilogramme. 

British  Thermal 
Units  per 
Cubic  Foot  to 
Calories  per 
Cubic  Meter. 

1 

1.8 

0.11236 

0.556 

8.898    ' 

2 

3.6 

.22472 

1.112 

17.796 

3 

5.4 

.33708 

1.668 

26.694 

4 

7.2 

.44944 

2.224 

35.592 

5 

9.0 

.56180 

2.780 

44.490 

6 

10.8 

.67416 

3.336 

53.388 

7 

12.6 

.78652 

3.892 

62  .  286 

8 

14.4 

.89888 

4.448 

71.184 

9 

16.2 

1.01124 

5.004 

80.082 

10 

18. 

1  .  1236 

5.560 

88.980 

15 

27. 

1.6854 

8.340 

133.470 

20 

36. 

2.2472 

11.120 

177.960 

25 

45. 

2.809 

13.900 

222.450 

30 

54. 

3.3708 

16.680 

266.940 

35 

63. 

3.9326 

19.460 

311.430 

40 

72. 

4.4944 

22.240 

355.920 

45 

81. 

5.0562 

25.020 

400.410 

50 

90. 

5.618 

27.800 

444.900 

55 

99. 

6.1798 

30.580 

489.390 

60 

108. 

6.7416 

33.360 

533.880 

65 

117. 

7.3034 

36  .  140 

578.370 

70 

126. 

7.8652 

38.920 

622.860 

75 

135. 

8.427 

41.700 

667.350 

80 

144. 

8.9888 

44.480 

711.840 

85 

153. 

9.5506 

47.260 

756.330 

90 

162. 

10.1124 

50.040 

800.820 

95 

171. 

10.6742 

52.820 

845.310 

100 

180. 

11.236 

55.600 

889.800 

200 

360. 

22.472 

111.200 

1779.600 

300 

540. 

33.708 

116.800 

2669.400 

44.944 

222.400 

359.200 

400 

720. 

56.180 

278. 

4419. 

500 

900. 

67.416 

333.600 

5339.200 

600 

1080. 

78.652 

389.200 

6228.600 

700 

1260. 

89.888 

444.800 

7118.400 

800 

1440. 

101.124 

500.400 

8008.200 

900 

1620. 

112.36 

556. 

8898. 

1000 

1800. 

372  AMERICAN  GAS-ENGINEERING  PRACTICE. 


CONVERSION  OF  DEGREES  CENTIGRADE  AND  FAHRENHEIT. 

In  the  centigrade  thermometer  the  freezing-point  of  water  is 
taken  as  0°,  and  on  the  Fahrenheit  scale  as  32°.  The  boiling-point 
of  water  is  taken  as  Iw00>onthe  former  and  as  212°  on  the  latter. 
This  gives  a  range  of  100  degrees  between  the  freezing-  and  boil- 
ing-points of  water  on  the  centigrade  scale,  and  of  180  degrees 
on  the  Fahrenheit  scale,  or  a  ratio  of  1  to  1.8.  Hence  to  change 
degrees  centigrade  to  Fahrenheit,  multiply  the  degrees  centi- 
grade by  1.8  and  add  32  to  the  product;  and  to  change  degrees 
Fahrenheit  to  centigrade,  subtract  32  from  the  degrees  Fahren- 
heit and  multiply  the  remainder  by  the  reciprocal  of  1.8  or  0.556. 

In  the  following  tables  are  tabulated  for  convenience  of  use 
the  comparative  values  on  the  two  scales. 


CONVERSION  FACTORS. 


373 


CONVERSION    OF   THERMOMETRIC    READINGS. 
Fahrenheit  to  Centigrade. 


F. 

c. 

F. 

'  C. 

F. 

C. 

F. 

C. 

-40° 

-40° 

1° 

-17.2° 

41° 

5.° 

81° 

27.2° 

-39 

-39.4 

2 

-16.6 

42 

5.5 

82 

27.7 

-38 

-38.8 

3 

-16.1 

43 

6.1 

83 

28.3 

-37 

-38.3 

4 

-15.5 

44 

6.6 

84 

28.8 

-36 

-37.7 

5 

-15. 

45 

7.2 

85 

29.4 

-35 

-37.2 

6 

-14.4 

46 

7.7 

86 

30. 

-34 

-36.6 

7 

-13.8 

47 

8.3 

87 

30.5 

-33 

-36.1 

8 

-13.3 

48 

8.8 

88 

31.1 

-32 

-35.5 

9 

-12.7 

49 

9.4 

89 

31.6 

-31 

-35. 

10 

-12.2 

50 

10. 

90 

32.2 

-30 

-34.4 

11 

-11.6 

51 

10.5 

91 

32.7 

-29 

-33.8 

12 

-11.1 

52 

11.1 

92 

33.3 

-28 

-33.3 

13 

-10.5 

53 

11.6 

93 

33.8 

-27 

-32.7 

14 

-10. 

54 

12.2 

94 

34.4 

-26 

-32.2 

15 

-  9.4 

55 

12.7 

95 

35. 

-25 

-31.6 

16 

-  8.8 

56 

13.3 

96 

35.5 

-24 

-31.1 

17 

-  8.3 

57 

13.8  t 

97 

36.1 

-23 

-30.5 

18 

-  7.7 

58 

14.4 

98 

36.6 

-22 

-30. 

19 

-  7.2 

59 

15. 

99 

37.2 

-21 

-29.4 

20 

-  6.6 

60 

15.5 

100 

37.7 

-20 

-28.8 

21 

-  6.1 

61 

16.1 

101 

38.3 

-19 

-28.3 

22 

-  5.5 

62 

16.6 

102 

38.8 

-18 

-27.7 

23 

-  5. 

63 

17.2 

103 

39.4 

-17 

-27.2 

24 

-  4.4 

64 

17.7 

104 

40. 

-16 

-26.6 

25 

-  3.8 

65 

18.3 

105 

40.5 

-15 

-26.1 

26 

-  3.3 

66 

18.8 

106 

41.1 

-14 

-25.5 

27 

-  2.7 

67 

19.4 

107 

41.6 

-13 

-25. 

28 

-  2.2 

68 

21.1 

108 

42.2 

-12 

-24.4 

29 

-  1.6 

69 

20. 

109 

42.7 

-11 

-23.8 

30 

-  1.1 

70 

20.5 

110 

43.3 

-10 

-23.3 

31 

-  0.5 

71 

21.6 

111 

43.8 

-  9 

-22.7 

32 

+  0 

72 

22.2 

112 

44.4 

-  8 

-22.2 

33 

+  0.5 

73 

22.7 

113 

45. 

-  7 

-21.6 

34 

1.1 

74 

23.3 

114 

45.5 

-  6 

-21.1 

35 

1.6 

75 

23.8 

115 

46.1 

-  5 

-20.5 

36 

2.2 

76 

24.4 

116 

46.6 

-  4 

-20. 

37 

2.7 

77 

25. 

117 

47.2 

-  3 

-19.4 

38 

3.3 

78 

25.5 

118 

47.7 

-  2 

-18.8 

39 

3.8 

79 

26.1 

119 

48.3 

-  1 

-18.3 

40 

4.4 

80 

26.6 

120 

48.8 

0 

-17.7 

374 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


CONVERSION   OF  THERMOMETRIC  READINGS— Continued. 
Fahrenheit  to  Centigrade. 


F. 

C. 

F. 

C. 

F. 

C. 

F. 

e. 

121° 

49.4° 

161° 

71.6° 

201° 

93.8° 

241° 

116.1° 

122 

50. 

162 

72.2 

202 

94.4 

242 

116.6 

123 

50.5 

163 

72.7 

203 

95. 

243 

117.2 

124 

51.1 

164 

73.3 

204 

95.5 

244 

117.7 

125 

51.6 

165 

73.8 

205 

96.1 

245 

118.3 

126 

52.2 

166 

74.4 

206 

96.6 

246 

118.8 

127 

52.7 

167 

75. 

207 

97.2 

247 

119.4 

128 

53.3 

168 

75.5 

208 

97.7 

248 

120. 

129 

53.8 

169 

76.1 

209 

98.3 

249 

120.5 

130 

54.4 

170 

76.6 

210 

98.8 

250 

121.1 

131 

55. 

171 

77.2 

211 

99.4 

251 

121.6 

132 

55.5 

172 

77.7 

212 

100. 

252 

122.2 

133 

56.1 

173 

78.3 

213 

100.5 

253 

122.7 

134 

56.6 

174 

78.8 

214 

101.1 

254 

123.3 

135 

57.2 

175 

79.4 

215 

101.6 

255 

123.8 

136 

57.7 

176 

80. 

216 

102.2 

256 

124.4 

137 

58.3 

177 

80.5 

217 

102.7 

257 

125. 

138 

58.8 

178 

81.1 

218 

103.3 

258 

125.5 

139 

59.4 

179 

81.6 

219 

103.8 

259 

126.1 

140 

60. 

180 

82.2 

220 

104.4 

260 

126.6 

141 

60.5 

181 

82.7 

221 

105. 

261 

127.2 

142 

61.1 

182 

83.3 

222 

105.5 

262 

127.7 

143 

61.6 

183 

83.8 

223 

106.1 

263 

128.3 

144 

62.2 

184 

84.4 

224 

106.6 

264 

128.8 

145 

62.7 

185 

85. 

225 

107.2 

265 

129.4 

146 

63.3 

186 

85.5 

226 

107.7 

266 

130. 

147 

63.8 

187 

86.1 

227 

108.3 

267 

130.5 

148 

64.4 

188 

86.6 

228 

108.8 

268 

131.1 

149 

65. 

189 

87.2 

229 

109.4 

269 

131.6 

150 

65.5 

190 

87.7 

230 

110. 

270 

132.2 

151 

66.1 

191 

88.3 

231 

110.5 

271 

132.7 

152 

66.6 

192 

88.8 

232 

111.1 

272 

133.3 

153 

67.2 

193 

89.4 

233 

111.6 

273 

133.8 

154 

67.7 

194 

90. 

234 

112.2 

274 

134.4 

155 

68.3 

195 

90.5 

235 

112.7 

275 

135. 

156 

68.8 

196 

91.1 

236 

113.3 

276 

135.5 

157 

69.4 

197 

91.6 

237 

113.8 

277 

136.1 

158 

70. 

198 

92.2 

238 

114.4 

278 

136.7 

159 

70.5 

199 

92.7 

239 

115. 

279 

137.2 

160 

71.1 

200 

93.3 

240 

115.5 

CONVERSION  FACTORS. 


375 


Inches  X        0 

Inches  X        0 

Inches  X  0 
Square  inches  X  0 
Square  inches  X  0 

Cubic  inches  X         0 

Cubic  inches  X         0 

Cubic  inches  X         0 

Feet  X         0 

Feet  X         0 

Square  feet  X     144 

Square  feet  X         0 

Cubic  feet  X   1728 

Cubic  feet  X         0 

Cubic  feet  X         7 

Yards  X       36 

Yards  X         3 

Yards  X  0 
Square  yards  X  1296 
Square  yards  X  9 

Cubic  yards  X  46656 

Cubic  yards  X       27 

Miles  X  63360 

Miles  X  5280 

Miles  X  1760 

Avoir,  oz.  X        0 

Avoir,  oz.  X        0 

Avoir.  Ibs.  X       16 

Avoir.  Ibs.  X         0 

Avoir.  Ibs.  X        0 

Avoir.  Ibs.  =       27 

Avoir,  tons  X  32000 

Avoir,  tons  X  2000 

Watts  X     746 

Horse-power  X         0 


USEFUL    FACTORS. 

.08333  =feet 

.02778  =  yards 

.00001578^miles 

.00695  =  square  feet 

.0007716  =square  yards 

.00058  =  cubic  feet 

.0000214  =  cubic  yards 

.004329  =U.S.  gallons 

.3334  =  yards 

.00019  =  miles 

.00  =  square  inches 

.1112  =  square  yards 

.00  =  cubic  inches 

.03704  =  cubic  yards 

.48  =  U.S.  gallons 

.000  =  inches 

.000  =feet 

.0005681  =  miles 

.000  =  square  inches 

.000  =  square  feet 

.  000  =  cubic  inches 

.000  =  cubic  feet 

.000  =  inches 

.000  =feet 

.00  =  yards 

.0625  =  pounds 

.00003 125  =  tons 

.000  =  ounces 

.  00 1  =  hundredweight 

.0005  =tons 

.  681  cu.  inches  of  water  at  39.2°  F. 

.00  =  ounces 

.00  = pounds 

.  00  =  horse-power 

.00134  =  watts 


Weight  of  round  iron   per  foot= square   of  diameter  in  quarter 

inches  -r-  6. 

Weight  of  flat  iron  per  f oot = width X  thickness  X 10. 3. 
Weight  of  flat  plates  per  square  foot =5  pounds  for  each  J  inch 

thickness. 

Weight  of  chain = diameter  squared X 10. 7  (approximately). 
Safe  load    (in  pounds)   for  chains = square  of  quarter  inches  in 

diameter  of  bar. 


376 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


WATER   FACTORS. 

U.  S.  gallons  X     8.33         -pounds 

U.  S.  gallons  X     0 . 13368  =  cubic  feet 

U.  S.  gallons  >  2?  1 . 00         =  cubic  inches 

U.  S.  gallons  X     0 . 83         =  English  gallons 

U.  S.  gallons  X     3 . 78         =  liters 

English  gallons  (Imperial)  X   10  = pounds 

English  gallons  (Imperial)  X     0.16         =  cubic  feet 

English  gallons  (Imperial)  X 277. 274       =  cubic  inches 

English  gallons  (Imperial)  X     1.2  =U.  S.  gallons 

English  gallons  (Imperial)  X     4 . 537       =  liters 

Cubic  feet  (of  water)  (39.1°)  X  62.425       =  pounds 

Cubic  feet  (of  water)  (39.1°)  X     7.48         =U.  S.  gallons 

Cubic  feet  (of  water)  (39.1°)  X     6.232       =  English  gallons 

Cubic  feet  (of  water)  (39.1°)  X     0.028       =tons 

Cubic  foot  of  ice  X  57.2          =  pounds 

Cubic  inches  of  water  (39. 1°)  X     0 . 036024  =  pounds 

Cubic  inches  of  water  (39.1°)  X     0. 004329 =U.  S.  gallons 

Cubic  inches  of  water  (39.1°)  X     0.003607= English  gallons 

Cubic  inches  of  water  (39. 1°)  X     0 . 576384 = ounces 

Pounds  of  water  X  27 . 72         =  cubic  inches 

Pounds  of  water  X     0.01602  =  cubic  feet 

Pounds  of  water  X     0.083       =U.  S.  gallons 

Pounds  of  water  X     0 . 10         =  English  gallons 

Tons  of  water  X  268 . 80         =  U.  S.  gallons 

Tons  of  water  X  224 . 00         =  English  gallons 

Tons  of  water  X  35.90         =  cubic  feet 

Ounces  of  water  X     1  -  735       =  cubic  inches 

A  column  of  water  1  inch  square  by   1  foot  high  weighs  0.434 

pound, 
A  column  of  water  1  inch  square  by  2.31  feet  high  weighs  1.000 

pound. 

Water  is  at  its  greatest  density  at  39.2°  F. 
Sea  water  is  1.6  to  1.9  heavier  +han  fresh. 
One  cubic    inch  of  water  makes   approximately  1  cubic  foot  of 

steam  at  atmospheric  pressure. 
27222  cubic  feet  of  steam  at  atmospheric  pressure  •  weigh  1  pound. 


CHAPTER  XXIII. 

PIPE  AND  MISCELLANEOUS  DATA. 

THE  formula  generally  used  for  calculating  the  capacity  of  a 
pipe  for  transmitting  gas  under  low  pressures  not  exceeding  the 
head  due  to  a  few  inches  of  water  column  is  credited  to  Dr.  Pole 
and  is 


where  Q=cu.  ft.  discharged  at  the  exit  end  per  hour; 

d=  internal  diameter,  inches; 

h  =  pressure  in  inches  of  water  column; 

1=  length  of  pipe  in  yards; 

g= specific  gravity  of  the  gas,  air=  1. 

Prof.  S.  W.  Robinson  of  Columbus,  Ohio,  has  deduced  the 
following  formula  for  high  pressures,  which  is  slightly  in  excess  of 
the  observed  results: 


y=48.4-= 


where  7  =  cubic  feet  per  hour  at  atmospheric  pressure  and  TI; 
TI  =  absolute  temperature  of  storage  =  461°  + reading  F°; 
T2=  absolute  temperature  of  gas  flowing  in  pipe-line  reading 

F°; 

TQ  =  absolute    temperature  =  461°  + 37°  F.  =  498°    (at    maxi- 
mum density  of  water) ; 
d5= diameter  of  pipe-line  in  inches; 
L  =  length  of  pipe-line  in  miles; 
p1  =  gage  pressure  at  entrance  end  of  gas-main,  pounds  per 

square  inch; 

p2=gage  pressure  at  exit  end  of  main,  pounds  per  square 
inch. 

377 


378 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


Some  of  the  data  found  valuable  in  connection  with  pipe  are 
given  herewith  in  the  following  tables: 


WROUGHT-IRON  WELDED  PIPE. 


(1  in.  diam.  and  below  are  butt-welded  and  tested  to  300  Ibs.  per  sq.  in. 
hydraulic  pressure;  1|  in.  and  above  are  lap-welded  and  tested  to  500  Ibs. 
per  sq.  in.  hydraulic  pressure.) 


Inside 
Diameter. 

Outside 
Diameter. 

External  Cir- 
cumference. 

Length  of  Pipe 
per  Sq.  Ft. 
of  Outside 
Surface. 

Internal  Area. 

External  Area 

Length  of  Pipe 
containing 
1  Cubic  Foot. 

Weight  per 
Foot  of 
Length. 

No.  of  Threads 
per  Inch  per 
Screw. 

Contents  in 
Gallons  * 
per  Foot. 

i! 

Inch. 

Inch. 

Inches. 

Feet. 

Inches. 

Inches. 

Feet. 

Lbs. 

Lbs. 

0.40 

1.272 

9.440 

0.012 

0.129 

2500.0 

0.24 

27 

0.0006 

0.005 

0.54 

1.696 

7.075 

0.049 

0.229 

1385.0 

0.42 

18 

0.0026 

0.021 

0.67 

2.121 

5.657 

0.110 

0.358 

751.5 

0.56 

18 

0.0057 

0.047 

0.84 

2.652 

4.502 

0.196 

0.554 

472.4 

0.84 

14 

0.0102 

0.085 

j 

1.05 

3.299 

3.637 

0.441 

0.866 

270.0 

1.12 

14 

0.0230 

0.190 

1 

1.31 

4.134 

2.903 

0.785 

1.357 

166.9 

1.67 

11} 

0.0408 

0.349 

l\ 

• 

1.66 

5.215 

2.301 

1.227 

2.164 

96.25 

2.25 

11} 

0.0638 

0.527 

Ij 

1.9 

5.969 

2.01 

1.767 

2.835 

70.65 

2.69 

11} 

0.0918 

0.760 

2 

2.37 

7.461 

1.611 

3.141 

4.430 

42.36 

3.66 

11} 

0.1632 

1.356 

2\ 

2.87 

9.032 

1.328 

4.908 

6.491 

30.11 

5.77 

8 

0.2550 

2.116 

3 

3.5 

10.996 

1.091 

7.068 

9.621 

19.49 

7.54 

8 

0.3673 

3.049 

3^ 

4. 

12.566 

0.955 

9.621 

12.566 

14.56 

9.05 

8 

0.4998 

4.155 

4 

4.5 

14.137 

0.849 

12.566 

15.904 

11.31 

10.72 

8 

0.6528 

5.405 

4J 

5. 

15.708 

0.765 

15.904 

19.635 

9.03 

12.49 

8 

0.8263 

6.851 

5 

5.56 

17.475 

0.629 

19.635 

24.299 

7.20 

14.56 

8 

1.020 

8.500 

6 

6.62 

20.813 

0.577 

28.274 

34.471 

4.98 

18.76 

8 

1.469 

12.312 

7 

7.62 

23.954 

0.505 

38.484 

45.663 

3.72 

23.41 

8 

1.999 

16.662 

8 

8.62 

27.096 

0.444 

50.265 

58.426 

2.88 

28.34 

8 

2.611 

21.750 

9 

9.68 

30.433 

0.394 

63.617 

73.715 

2.26 

34.67 

8 

3.300 

27.500 

10 

10.75 

33.772 

0.355 

78.540 

90.792 

1.80 

40.64 

8 

4.081 

34.000 

*  The  Standard  U.  S.  gallon  of  231  cubic  inches. 

Equation  of  Pipes. — It  is  frequently  desired  to  know  what 
number  of  pipes  of  a  given  size  are  equal  in  carrying  capacity  to 
one  pipe  of  a  larger  size.  At  the  same  velocity  of  flow  the  volume 
delivered  by  two  pipes  of  different  sizes  is  proportional  to  the 
squares  of  their  diameters;  thus,  one  4-inch  pipe  will  deliver  the 
same  volume  as  four  2-inch  pipes.  With  the  same  head,  however, 
the  velocity  is  less  in  the  smaller  pipe  and  the  volume  delivered 
varies  about  as  the  square  root  of  the  fifth  power  (i.e.,  as  the  2.5 
power).  The  following  table  has  been  calculated  on  this  basis. 
The  figures  opposite  the  intersection  of  any  two  sizes  is  the  number 
of  the  smaller-sized  pipes  required  to  equal  one  of  the  larger.  Thus, 
one  4-inch  pipe  is  equal  to  5.7  2-inch  pipes. 


PIPE  AND  MISCELLANEOUS  DATA. 


379 


3 


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81 


380  AMERICAN  GAS-ENGINEERING  PRACTICE. 

PIPING   AND    PIPE-FITTINGS. 

The  Crane  Co.  of  Chicago,  111.,  have  conducted  tests  on  piping, 
and  some  of  the  conclusions  were  presented  in  a  paper  before 
the  Engine  Builders'  Association  at  the  spring  meeting,  1902,  by 
J.  B.  Berryman.  The  following  is  abstracted: 

Strength  of  Ordinary  Commercial  Pipe. — Tests  of  lengths 
taken  at  random  out  of  stock:  8-in.  stood  2000  Ibs.;  10-in.  2300 
Ibs.;  12-in.  1500  Ibs.;  16-in.,  }  in.  thick,  800  Ibs.;  and  24-in.,  J  in. 
thick,  600  Ibs.  per  sq.  in.  without  rupture  or  distortion.  Thou- 
sands of  pieces  of  20-in.  size  and  under  have  stood  800  Ibs.  per 
sq.  in.  Hence  there  is  no  reason  why  pipe  heavier  than  standard 
should  be  used  in  power  plants,  except  where  water  is  bad  and 
there  may  be  corrosion. 

Flanged  Joints. — Most  of  our  orders  are  for  screwed  or  shrunk 
flanges  in  the  ratio  of  85  screwed  to  15  shrunk.  We  prefer  the 
screwed  joint  and  use  the  following  lengths  of  thread,  those  first 
given  being  for  pressures  up  to  125  Ibs.  and  those  in  last  column 
for  pressure  up  to  250  Ibs. 

Diameter,  Pipe.  Thread  Lengths. 

4-in.  1A  1} 

6-in.  1&  2 

8-in.  If  2& 

12-in.  2^  2& 

16-in.  2^  2J 

20-in.  2|  3J 

Assuming  a  shearing  strength  of  one-half  tensile  strength,  the 
above  proportions  give  a  holding  power  fully  three  times  ultimate 
strength  of  pipe.  We  have  tested  joints,  starting  with  long  threads 
on  pipe,  as  per  above  table,  and  gradually  cutting  threads  away. 
In  no  case  were  threads  stripped,  and  results  show  that  strength 
of  joints  was  limited  by  strengths  of  the  cast-iron  flanges.  On  a 
10-inch  pipe  threads  were  reduced  until  only  5  remained.  Flanges 
broke  at  650  pounds  pressure,  all  threads  remaining  intact.  A  cal- 
culation of  the  amount  of  metal  which  would  have  to  be  sheared 
off  before  a  joint  parted  will  show  that  there  is  no  likelihood  of 
the  threads  stripping.  Taking  our  standard  length  of  thread, 
eight  per  inch,  the  results  work  out  as  follows: 

T        ,,     r  Metal  in  Sectional 

Size.  TH      H  Contact,  Area  of  Full- 

Square  Inches.          weight  Pipe. 

8  1|  42  8.396 

12  2^  77  14.579 

16f  2&  116  18.41 


PIPE  AND  MISCELLANEOUS  DATA.  381 

Mess.  Crane  made  a  great  number  of  tests  on  8-in.  pipe,  using 
regular  wrought-iron  couplings  to  demonstrate  that  long  threads 
are  not  necessary  to  strength.  Final  tests  were  made  with  barely 
6  threads  in  contact,  and  f  inch  length  of  threaded  part.  The 
pipe  was  tested  to  1000  pounds,  the  pressure  being  held  a  day 
without  giving  way.  The  only  object  in  using  long  threads  is  to 
make  a  tight  joint  and  not  to  gain  strength.  Pipe  should  be 
screwed  clear  through  flange  to  guard  against  vibration  and  make 
a  bearing  for  gasket  on  end  of  pipe  and  close  thread  against  oxi- 
dizing action  of  steam.  Screw  flange  on  by  power  until  pipe  pro- 
jects TS  in.;  then  face  off  end  of  pipe  and  face  true  with  axis  of 
pipe.  In  making  shrunk  joints  the  pipe  is  rounded  up  and  calipered, 
flange  bored  out  to  a  shrinking-fit  size,  brought  to  red  heat,  the 
pipe  slipped  in  and  peened  over. 

Facing  Flanges. — Flanges  are  generally  made  with  straight 
face  finished  smooth,  straight  face  finished  corrugated,  male  and 
female,  tongue  and  groove  and  -h  in.  raised  face  inside  bolt-holes. 
For  pressure  of  180  Ibs.  or  less  our  experiments  show  that  a  straight, 
concentrically  corrugated  face  will  hold  a  Rainbow  or  copper 
gasket.  Have  made  repeated  tests  with  pressures  up  to  1000 
pounds  without  blowing  out  the  gasket. 

Flanges.— There  are  two  recognized  standards  for  flanges. 
One,  for  pressures  up  to  125  Ibs.,  was  adopted  by  a  joint  committee 
of  the  A.  S.  M.  E.,  the  Master  Steam  Fitters'  Association,  and 
the  manufacturers.  The  other,  for  pressures  up  to  2£0  Ibs.,  was 
adopted  at  a  meeting  of  the  manufacturers  held  in  New  York, 
June  28,  1901,  and  is  generally  referred  to  as  the  "Manufacturers7 
Standard." 

Flanged  Fittings. — We  manufacture  these  in  three  weights  for 
pressures  up  to  50,  125,  and  250  Ibs.  respectively.  The  thickness 
of  the  body  metal  of  each  is  as  follows: 

Diameter  Pipe.  Light.  Standard.         Extra  Heavy. 

6-in.  &                       f 

10-in.  f  if 

12-in.  I  H  1 

16-in.  f  1  1& 

20-in.  ft  l.i  1& 

24-in.  f  1J  1| 

These  thicknesses  give  factors  of  safety  of  10  or  12,  when  com- 
puted by  the  formula  for  pipes,  which  is  desirable,  since  tests  show 
that  fittings  burst  at  pressures  less  than  indicated  by  theory. 

Valves. — Valves  are  made  of  same  thickness  as  the  flanged 
fittings  and  designed  for  corresponding  pressures.  The  standard 


382 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


valves,  4-in.  to  8-in.,  will  burst  at  about  700  Ibs.;  10-in.  to  16-in. 
at  about  600  Ibs.  The  extra  heavy  valves,  4-in.  to  8-in.,  burst 
at  1600  to  1900  Ibs.;  10-in.  to  16-in.  at  about  1200  to  1500. 
A  medium  valve  is  also  made  for  pressures  between  those  for 
which  the  standard  and  extra-heavy  valves  are  designed.  In  all 
these  cases  the  valves  were  of  the  solid  wedge  type,  and  it  was 
found  that  their  disks  would  stand  about  80  per  cent,  of  the  burst- 
ing pressure  without  leaking.  It  would  not  be  possible  to  obtain 
equivalent  results  from  parallel-seated  double-disk  valves,  as  their 
disks  have  comparatively  light  faces,  set  out  by  an  internal  wedg- 
ing mechanism,  and  will  spring  under  pressure.  It  is  not  con- 
sidered desirable  to  rib  the  bodies  of  heavy  valves  owing  to  unequal 
strains.  For  high  pressures  use  valves  without  outside  screw  and 
yoke. 

Pipe-bends. — Unless  of  very  short  radius,  they  are  generally 
made  of  standard  pipe  for  pressures  of  125  pounds  or  less,  full- 
weight  pipe  up  to  175  pounds,  and  extra-heavy  pipe  for  higher 
pressures. 


WHITWORTH'S.  SCREW-THREADS. 
GAS-  AND  WATER-PIPING. 


Diameter  of  Piping. 

Diameter 

Diameter  of  Piping. 

Diameter 

at 

No.  of 

at 

No.  of 

Bottom 

Threads 

Bottom 

Threads 

In- 
ternal. 

External. 

of 
Thread. 

per  Inch. 

In- 
ternal. 

External. 

of 
Thread. 

per  Inch. 

0.3825 

0.3367 

28 

11 

2.245 

2.1285 

0.518 

0.4506 

19 

2 

2.347 

2.2305 

0.6563 

0.5889 

19 

2\ 

2.467 

2.3505 

0.8257 

0.7342 

14 

2] 

2.5875 

2.4710 

0.9022 

0.8107 

14 

2\ 

2.794 

2.3775 

1.041 

0.9495 

14 

2i 

3.0013 

2.8848 

1.189 

1.0975 

14 

2| 

3.124 

3.0075 

U" 

1.309 

1  .  1925 

2| 

3.247 

3.1305 

1.492 

1.3755 

25 

3.367 

3.2505 

1.650 

1.5335 

3 

3.485 

3.3685 

1.745 

1.6285 

•    11 

31 

3.6985 

3.5820 

1.8825 

1.7660 

si 

3.912 

3.7955 

1 

2.021 

1.9045 

sf 

4.1255 

4.0090 

1' 

2.047 

1.9305 

J 

4 

4.339 

4.2225 

PIPE   AND  MISCELLANEOUS  DATA. 


383 


ijri 

r~ 


^— I—I-HOOOOOOOOOOOOOOOOOOOOOOOOOOOOCX500 


ill 


<—  i  O  O  Oi  O5  00 


oooo<—  1 


o  o  fl 

ill 

5*0 


'—  i  oo  i—  i  co  o  i 


i—  i  i—  i<N<MCOtOOOOOCOcOCiCOcOO 
^^,-,0,0,  co 


<M  IM  c^j  co  co  "*  ^t1  -*  us  10 


§1 


^ 


i—  i  <M  CM  CO 


C4  CO  f-  O 


rH  CO  Tfi  l>  O  iO  00  CO  OQ  00  1-1  <M  O5  CO  i-H  (M 
TH  i—  I  (N  ^t1  l>-  O  CO  CO  t^  !>•  CO  CO 

r-l  T-H  (M  < 


1  -I 

Sf  g       e 

IM 


CO  -—I  b-  00  CO  CO 

t^rfii— i't|co^icooocO'-t<oor^ 

tOOO5OCOCOOifd»OOOQOoOCOcOO5O5-^^CO^O 
O'-t'-'COtOOOTtHOCOt^COOOt^ 


rH  TH  CO  -*f  00        i— i  l>  00  t^  00  CO 


1  co  c^j  Is*  o^ 


3g        Q 


OOOOi— I"-*!— ii— ( 


o3 

lal     ^ 


rH  i-l  r-(  (M  <N  CO  CO  ^  -^  tO  CO  t^  00  O5  O  ^-«M  Q  Q  Q 


384 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


"0*0  a 
®«.8  N 
S1S  S? 


cS  >> 

tfo 


. 

C  g  CO  -f  K3  00 

|1^;S|3SS3 

0)  O 

ME 


6- 


I* 


(M  ^ 


t>rf«5C^rfO 


rH  rH  i-t  i— I  C<1 


1—  1   Tt<   CO   i-t 


10CO 

r-l  CO 


^COt^ 
O  i—  i(N 


i"^  ^O  "^  CO  CO  CO  *O 

O5iOOOr-(cOcOt^ 


PIPE  AND   MISCELLANEOUS  DATA. 


385 


STANDARD   WROUGHT-IRON   AND  STEEL-PIPE   DIMENSIONS. 
(Pipes  li  in.  diam.  and  smaller  are  butt  welded;    1£  in.  diam.  and  larger  are  lap  welded.) 


Size,  Diam., 
Inches. 

Thickness 
of  Wall, 
Inches. 

Area  of 
Opening. 
Sq.  Inches. 

Actual 
Outside 
Diameter, 
Inches. 

Nominal 
Weight  per 
Foot,  Lbs. 

Number  of 
Threads  per 
Inch  of 
Screw. 

j  . 

0.068 

0.0573 

0.405 

0.24 

27 

'.  . 

0.088 

0.1041 

0.54 

0.42 

18 

l 

0.091 

0.1917 

0.675 

0.56 

18 

'.  . 

0.109 

0.3048 

0.84 

0.84 

14 

\ 

0.113 

0.5333 

1.05 

1.12 

14 

1 

0.134 

0.8626 

1.315 

1.67 

11* 

11 

0.140 

1.496 

1.66 

2.24 

H| 

1* 

0.145 

2.038 

1.9 

2.68 

n| 

2 

0.154 

3.356 

2.375 

3.61 

Hi 

zi 

0.204 

4.784 

2.875 

5.74 

8 

3 

0.217 

7.388 

3.5 

7.54 

8 

3i 

0.226 

9.887 

4. 

9. 

8 

0.237 

12.73 

4.5 

10.66 

8 

4* 

0.246 

15.961 

5. 

12.49 

8 

5 

0.259 

19.99 

5.563 

14.5 

8 

6 

0.28 

28.888 

6.625 

18.76 

8 

7 

0.301 

38.738 

7.625 

23.27 

8 

8 

0.322 

50.04 

8.625 

28.18 

8 

9 

0.344 

62.73 

9.625 

33.7 

8 

10 

0.366 

78.839 

10.75 

40. 

8 

11 

0.375 

95.033 

11.75 

45. 

8 

12 

0.375 

113.098 

12.75 

49. 

8 

13 

0.375 

137.887 

14. 

54. 

8 

14 

0.375 

159.485 

15. 

58. 

8 

15 

0.375 

187.04 

16. 

62. 

8 

386 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


WEIGHT  OF  MALLEABLE-IRON   FITTINGS   FOR  GAS-PIPE. 


Size, 
Inches. 

Lbs.  per 
Hundred. 

Size, 
Inches. 

Lbs.  per 
Hundred. 

Size, 
Inches. 

Lbs.  per 
Hundred. 

ELBOWS,  90  DEGREES. 

SHORT  FEMALE  DROP 
•ELBOWS. 

TEES. 

i 

8 

i 

13 

*xlx* 

22 

ixi 

7* 

fxl 

22 

*xi 

Xi 

20 

i 

8* 

f 

19 

*Xi 

Xf 

24* 

m 

14* 
14 

*xf 

27 

27 

Ixi 

x* 

26* 
32* 

f 

15 

IX* 

40* 

*xi 

21 

*xi 

Ixi 

22* 
19* 
22 

1                     41* 

SHORT  MALE  AND  FEMALE 
DROP  ELBOWS. 

*xf 
ixi 

26 
29* 

fxf 

if! 

31 
35 
33* 

ixf 
ixf 

12 
16* 

*> 
*> 
i  xi 

Cl 

/  1  1 

"xf 

34* 
75 
29 

ix* 

47* 

f 

26 

-x* 

35* 

ixi 

45 

LONG  MALE  AND  FEMALE 

i  XJ 

-xi 

30* 

1 

42* 

DROP  ELBOWS. 

!  Xj 

xi 

50 

ilxl 

11X1 

83 

88* 

IX! 

16 
26 

i  X*Xr 

i  x*xi 

33 
29 

11 

76 

o                                           —  — 

\  XfXji 

34 

i*x| 

102* 

SIDE  OUTLET  ELBOWS. 

i  XlXJ 

38 

1*X1 

94* 
101 

fxfxi 

12 
16 

\  x*xi 
ixi 

50* 
29* 

2X11 

105 
176 

*x*xf 

19* 
2Q 

IX* 

30* 
34 

2X1* 
2 

169 
169* 

ixlxf 
ixix* 

££9 

37 
38 

ixi 

41 
34 

ELBOWS,  45  DEGREES. 

8                     121 

ixixf 

40 
48 

ixi* 

64 
69 

116* 

ixix* 

49* 

ixi 

X| 

44* 

I 

v  * 

31 

ixixl 

51* 

}x 

x| 

47* 

1 

49 

1 

55* 

IX 

-xi 

54 

11 

83* 
118 

11 

87 
9U 

ixfxii 
ix*xf 

67* 
37* 

A2 

17O 

ix*x* 

42 

TEES. 

ix*x| 

40* 

STREET  ELBOWS. 

.J 

9 

ix*xi 

48 

f 

16 

iXl 

8 

ix*xii 

68 

I 

26 

ixi 

9* 

ixi 

xf 

39* 

IX* 

44 

12 

IX: 

x* 

44 

47 

ixf 

16 

1  X  J 

X| 

38 

ix| 

72 

fxixi 

15 

IX: 

xi 

49 

1 

73    , 

fxixf 

18* 

ixi 

xil 

67* 

iixi 

107 

fxi 

16 

i> 

37 

11 

114 

fxi 

15 

ixi 

35 

153 

f 

16* 

ix* 

41* 

1* 

158 

fx* 

24 

ixi 

50* 

2X1* 

229 

fxf 

27 

] 

I 

53 

2 

260 

*xlxl 

.        18* 

iX 

11 

60* 

PIPE  AND   MISCELLANEOUS  DATA. 


387 


WEIGHT  OF   MALLEABLE-IRON   FITTINGS   FOR  GAS-PIPE— Continued. 


Size, 
Inches. 

Lbs.  per 
Hundred  . 

Size, 
Inches. 

Lbs.  per 
Hundred. 

Size, 
Inches. 

Lbs.  per 
Hundred. 

TEES. 

TEES. 

MALE  AND  FEMALE  DROP 

TEES. 

1\ 
1 

i 

1X1} 

xf  xi 
xfxil 
x}xi 
x}xil 
•xixi 

109 
83 
89 
83 
94 
67 

79 

2Xl}X2 
2Xf 
2X} 
2X| 
2X1 
2X11 

214 
118 
120 
107 
130 
152 

I  XlXf 

ixixf 

fwith2}"l 
drop      / 

MALE  AND  FE 

TENSION    ] 

44 
37 

25} 

MALE    EX- 
>IECES. 

i 

xfxii 

i  £ 

89 

2X1} 
o 

154 

1Q7 

1 

•                      9* 

i 

xixf 

56 

\ 

r 

15 

l| 

XIX} 

47 

SIDE  OUTLET  TEES. 

, 

22} 

I: 

xixi 

65 

32i 

]_; 

xixi 

74 

1 

28} 

a 

lj 

xixij 

92 

I 

46 

R. 

H.  COUPLINGS. 

|j 

XIX} 

109 

1 

56} 

i|xl 

63 

H 

102 

} 

• 

*t 

66 

1 

; 

7 

iixi 

71 

FEMALE  DROP  TEES. 

; 

10} 

] 

li 

ijxi 
H 

LlXl} 

x}xi 

80 
90 
89 
91 

ixj 

ix] 

x| 

15} 
20} 
21 

1 

11 

17 
25 
40} 
53 

*1 

1} 
i  i 

X}X1} 

\/  3  v/  1  1 

113} 
on 

ixj 

xl 

16 
21 

$ 

80 
127 

1^/\I  /\  AJ 

1}X!X1} 

i}xix| 

%/u 
114 
81 
91 

}xi 

xi 

fXi! 

27 
26} 
16 
33 

R.  &  L.  COUPLINGS. 
\-                     9 

i}xixil 

94 

!i 
s  vl.v.1 

31 

| 

13 

i}xilxf 

109 

82 

t      /N  * 

/N    , 

x- 

37} 
35 

17} 
29 

1} 

xitxi 

91 

1  xi 

34 

] 

i 

50} 

i} 
i} 

XllXll 
xilxi} 

96 
110 

i  xi 

•xii 

42 
49} 

1 

1 

I 

72 
106 

1    Xf 

1       vy  1 

85 

TTL 

ixi 

xf  • 

^  2 

46 

2 

152 

15  A$ 

1    X| 
1   XI 
liXH 

77} 
91} 
102 
102 

ixixf 
ixix} 
ixixf 

43 
58 
63 

REDUCING  C< 
IX} 

)UPLINGS. 

6} 

1}X2 

126 
131} 

MALE  AND  FEMALE  DROP 
TEES. 

ixi 

ixi 

9 

7} 

2X}X2 

250 

}> 

Cl 

12 

2X|X2 

203 

lx 

Xf 

17 

}Xf 

14 

2X1X2 

221 

f  X 

;Xf 

14} 

ixi 

21 

2XHX11 

172 

i 

18} 

Xf 

21 

2X11X1} 

146 

xi 

181 

i  X} 

22 

2XHX2 

203 

}x 

26 

ixt 

33 

2Xl}XH 

155 

fx 

Xi 

33 

ixi 

33 

2Xl}Xl} 

169 

Ixi 

xi 

36 

IX} 

36 

388 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


WEIGHT  OF  MALLEABLE-IRON   FITTINGS    FOR  GAS-PIFE^Continued. 


Size, 
Inches. 

Lbs.  per 
Hundred. 

Size, 
Inches. 

Lbs.  per 
Hundred. 

Size, 
Inches. 

Lbs.  per 
Hundred. 

REDUCING  COUPLINGS. 

CROSSES. 

CLOSE  PATENT  RETURN 
BENDS. 

1X1 

31 

IX* 

38* 

| 

30* 

Uxt 

54* 

1 

37* 

1 

88 

HX* 

Hxl 
ifxi 

i*x* 
i*x| 

53 

47 
53 
68 
69 

ixfxi 
ixfxi 

ixlx* 
ixfxi 

1X1 

37 
39 

50* 
54* 
42 

H 
1* 

2 

OPEN  PATENT 
BEN 

oo 

152 
228 
333 

"  RETURN 

i*xi 

59 

IX* 

32 

* 

35 

]i  X  11 

70 

1 

x  I 

37 

I 

104 

2X| 

85 

1 

59 

4 

1 

134 

2X* 

90 

Hxixi 

73* 

202* 

2X| 

102 

Hxixi 

83 

1* 

w      2 

251 

2X1 

125* 

1- 

'  Xf 

65 

2 

454 

2XH 

91 

1 

'X* 

71* 

2X1* 

108* 

1 

tX* 

86 

i 

3 

1 

92 

| 

5* 

CROSSES. 

H 

100 

8 

I 

7* 

i 

13* 

1*X 

92 

2 

11* 

|Xi 

16 

fXf 

85 

1 

19 

; 

19* 

I] 

x  * 

87 

11 

27 

*xfxi 

22 

li 

x| 

108 

4 

34 

23* 

xi 

100 

o 

48i 

*xgx* 

25 

ii 

xu 

121 

CAPS. 

*Xi 

13* 

i* 

142 

5* 

*xf 

23* 

2 

x* 

101 

3 

*•*  2 

8 

29* 

2X| 

122 

1 

11* 

iXfX* 

34* 

2X1 

118 

3 

2 

19 

1  x*xf 

26 

2.X  1J 

162 

1 

30 

|X*X* 

36* 

2X1* 

149 

40 

32 

2 

218 

li 

70 

2                      97 

DIMENSIONS   OF   FLANGE   PIECES. 


"8 

j. 

•3  . 

Q) 

o 

oT 

1|| 

|fi 

|E| 

Ill 

ft. 

II 

1 

1 

•£ 
'    I 

o 
PQ 

II 

0 

1 

-*-*  Q  P^ 

13  o 

'^  o  fa 

SO  W 

°3  o  O 

3  O 

^ 

03 

"o 

gw 

2^ 

^aj 

£ 

H 

£ 

o 

Q 

Q  ° 

O 

J 

s 

i8 

Ins. 

Ins. 

Ins. 

Ins. 

Ins. 

Im 

i. 

In 

s. 

Ins. 

Ins. 

Ins. 

30 

I 

1| 

37* 

34* 

20 

1 

.     j 

4 

25 

7 

24 
20 

| 

31 

27 

28* 
24* 

16 
16 

i 

• 

4 

4 

22 
20 

7 
7 

16 

f 

| 

22* 

20 

12 

1 

• 

3 

17 

6 

12 

Z 

18 

15| 

8 

2* 

14 

5 

10 

1 

| 

16 

13| 

8 

2* 

12 

4 

8 

A 

! 

13 

Ml 

8 

2* 

10 

4 

6 

1 

1 

11 

9* 

4 

2 

8 

3 

4 

1 

f 

9 

91 

4 

i 

\ 

2 

6 

2 

4 

A 

7f 

51 

4 

] 

; 

f 

2 

5 

2 

PIPE  AND   MISCELLANEOUS  DATA. 


389 


WEIGHT  AND   THICKNESS   OF   LEAD   PIPE. 


Caliber. 

Mark. 

Weight  per 
Foot. 

Thickness. 

Mean  Burst- 
ing Pressure. 

Safe  Work- 
ing Pressure. 

In. 

Lb.    Oz. 

In. 

Lbs.  per 
Sq.  In. 

Lbs.  per 
Sq.In. 

f 

AAA 

1      12 

0.180 

1968 

492 

AA 

1       5 

0.150 

1627 

406 

A 

1       2 

0.130 

1381 

347 

B 

1       0 

0.125 

1342 

335 

1 

C 

0     14 

0.110 

1187 

296 

| 

0     10 

0.087 

1085 

271 

& 

.  .  . 

0       9i 

0.080 

775 

193 

AAA 

3       0 

0.250 

1787 

446 

I 

.... 

2       8 

0.225 

1655 

413 

I 

AA 

2       0 

0.180 

1393 

343 

A 

1     10 

0.160 

1285 

321 

B 

1       3 

0.125 

980 

245 

C 

1       0 

0.100 

782 

195 

D 

0      9 

0.065 

468 

117 



0     10 

0.070 

556 

139 

0     12 

0.090 

625 

156 

, 

AAA 

3       8 

0.230 

1548 

387 

AA 

2     12 

0.210 

1380 

345 

, 

A 

2       8 

0.180 

1152 

288 

B 

2       0 

0.160 

987 

246 

i 

C 

1       7 

0.117 

795 

198 

D 

1       4 

0.100 

708 

177 

i 

AAA 

4     14 

0.290 

1462 

365 

• 

AA 

3       8 

0.225  * 

1225 

306 

i 

A 

3       0 

0.190 

1072 

268 

I 

B 

2       3 

0.150 

865 

216 

C 

1     12 

0.125 

782 

195 

| 

D 

1       3 

0.090 

505 

126 

1 

AAA 

6       0 

0.300 

1230 

307 

1 

AA 

4       8 

0.230 

910 

227 

1 

A 

4       0 

0.210 

857 

214 

1 

B 

3       4 

0.170 

745 

186 

1 

C 

2       8 

0.140 

562 

140 

1 

D 

2       4 

0.125 

518 

129 

1 

E 

2       0 

0.100 

475 

118 

1 

1       8 

0.090 

325 

81 

1 

AAA 

6     12 

0.275 

962 

240 

1 

AA 

5     12 

0.250 

823 

205 

1- 

A 

4     11 

0.210 

685 

171 

1- 

B 

3     11 

0.170 

546 

136 

390 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


WEIGHT  AND  THICKNESS  OF  LEAD   PIPE— Continued. 


Caliber. 

Mark. 

Weight  per 
Foot. 

Thickness. 

Mean  Burst- 
ing Pressure. 

Safe  Work- 
ing Pressure. 

In. 

Lb.    Oz. 

In. 

Lbs.  per 
Sq.  In. 

Lbs.  per 
Sq.  In. 

ii 

r 

C 

3        0 

0.135 

420 

105 

i 

D 

2      8 

0.125 

350 

87 

i* 

2      0 

0.095 

322 

80 

1\ 

r 

AA 

8      0 

0.290 

742 

185 

1< 

AA 

7      0 

0.250 

700 

175 

ia 

A 

6      4 

0.220 

628 

157 

li 

B 

5      0 

0.180 

506 

126 

; 

C 

4      4 

0.150 

430 

107 

;  J 

D 

3      8 

0.140 

315 

78 

I 



3      0 

0.120 

245 

61 

a 

, 

B 

5       0 

116 

I 

. 

C 

4      0 

93 

\ 

, 

D 

3     10 

0.125 

sis 

79 

2 

AAA 

10     11 

0.300 

611 

152 

2 

AA 

8     14 

0.250 

511 

127 

2 

A 

7      0 

0.210 

405 

101 

2 

B 

6      0 

0.190 

360 

90 

2 

C 

5      0 

0.160 

260 

65 

2 

D 

4      0 

0.090 

200 

50 

WEIGHTS   OF  STANDARD  GAS-PIPE. 


Internal 
Diameter 
in  Inches. 

Thickness 
of  Shell 
in  Inches. 

Weight 
per  Foot 
in  Pounds. 

Weight 
per  Pipe 
in  Pounds. 

Laid  Length. 

2 

A 

6 

48 

8 

3 

& 

12| 

150 

12 

4 

1 

17 

204 

12 

5 

ifa 

24 

288 

12 

6 

A 

30 

360 

12 

8 

1*5 

40 

480 

12 

10 

A 

50 

600 

12 

12 

| 

70 

840 

12 

14 

16 

84 

1000 

12 

16 

16 

100 

1200 

12 

18 

H 

134 

1600 

12 

20 

H 

150 

1800 

12 

24 

1 

184 

2200 

12 

PIPE  AND  MISCELLANEOUS  DATA. 


391 


APPROXIMATE   SQUARE    FEET   OF   RADIATING   SURFACE    OF   PIPE    PER 

LINEAL   FOOT. 
(On  all  lehgths  over  one  foot  fractions  less  than  tenths  are  added  to  or  dropped.) 


• 

f= 

Diameter  of  Pipe. 

r 

1 

l 

H 

H 

2 

2* 

3 

4 

5 

6 

7 

8 

i 

.275 

.346 

.434 

.494 

.622 

.753 

.916 

1  .  175 

1.455 

1.739 

1.996 

2.257 

2 

0.5 

0.7 

0.9 

1. 

1.2 

1.5 

1.8 

2.4 

2.9 

3.5 

4. 

4.5 

3 

0  8 

1 

1.3 

1.5 

1.9 

2.3 

2.7 

3.5 

4.4 

5.2 

6 

6  8 

4 

1.1 

1.4 

1.7 

2. 

2.5 

3. 

3.6 

4.7 

5.8 

7. 

8. 

9. 

5 

1  4 

1   7 

2.2 

2.4 

3.1 

3.8 

4.6 

5.8 

7.3 

7.7 

10 

11  3 

6 

1.6 

2.1 

2.6 

2.9 

3.7 

4.5 

5.5 

7. 

8.7 

10.5 

12. 

13.5 

7 

1.9 

2.4 

3. 

3.4 

4.4 

5.3 

6.4 

8.2 

10.2 

12.1 

14. 

15.8 

8 

2.2 

2.8 

3.5 

3.9 

5. 

6. 

7.3 

9.4 

11.6 

13.9 

16. 

18. 

9 

2.5 

3.1 

3.9 

4.4 

5.6 

6.8 

8.2 

10.6 

13.1 

15.7 

18. 

20.3 

10 

2.7 

3.5 

4.3 

4.9 

6.2 

7.5 

9.1 

11.8 

14.6 

17.4 

20. 

22.6 

11 

3. 

3.8 

4.8 

5.4 

6.8 

8.3 

10. 

12.9 

16. 

19.1 

22. 

24.9 

12 

3.3 

4.1 

5.2 

5.9 

7.5 

9. 

11. 

14.1 

17.4 

20.9 

24. 

27.1 

13 

3.6 

4.5 

5.6 

6.4 

8.1 

9.8 

11.9 

15.3 

18.9 

22.6 

26. 

29.4 

14 

3.8 

4.8 

6.1 

6.9 

8.7 

10.5 

12.8 

16.5 

20.3 

24.3 

28. 

31.6 

15 

4.1 

5.2 

6.5 

7.4 

9.3 

11.3 

13.7 

17.6 

21.8 

26.1 

30. 

33.9 

16 

4.4 

5.5 

6.9 

7.9 

10. 

12., 

14.6 

18.8 

23.2 

27.8 

32. 

36.1 

17 

4.7 

5.9 

7.4 

8.4 

10.6 

12.8 

15.5 

20. 

24.7 

29.5 

34. 

38.4 

18 

5. 

6.2 

7.8 

8.9 

11.2 

13.5 

16.5 

21  .2 

26.2 

31.3 

36. 

40.6 

19 

5.2 

6.6 

8.3 

9.4 

11.8 

14.3 

17.4 

22.3 

27.6 

33.1 

38. 

42.9 

20 

5.5 

6.9 

8.7 

9.9 

12.5 

15. 

18.3 

23.5 

29.1 

34.8 

40. 

45.2 

21 

5.8 

7.3 

9.1 

10.4 

13. 

15.8 

19.2 

24.7 

30.5 

36.5 

42. 

47.4 

22 

6. 

7.6 

9.6 

10.9 

13.7 

16.5 

20.2 

25.9 

32. 

38.3 

44. 

49.7 

23 

6.3 

8. 

10. 

11.3 

14.3 

17.3 

21.1 

27. 

33.5 

40. 

46. 

52. 

24 

6.6 

8.3 

10.4 

11.9 

14.9 

18. 

22. 

28.2 

34.9 

41.7 

48. 

54.2 

25 

6.9 

8.6 

10.9 

12.3 

15.6 

18.8 

22.9 

29.3 

36.3 

43.5 

50. 

56.4 

26 

7.1 

9. 

11.3 

12.8 

16.2 

19.5 

23.8 

30.5 

37.8 

45.2 

52. 

58.6 

27 

7.4 

9.4 

11.7 

13.3 

16.8 

20.3 

24.7 

31.7 

39.3 

47. 

54. 

61. 

28 

7.7 

9.7 

12.2 

13.8 

17.4 

21. 

25.6 

32.9 

40.7 

48.7 

56. 

63.2 

29 

8. 

10. 

12.6 

14.3 

18. 

21.8 

26.6 

34.1 

42.2 

50.4 

58. 

65.5 

30 

8.3 

10.4 

13. 

14.8 

18.7 

22.5 

27.5 

35.3 

43.6 

52.1 

60. 

67.7 

31 

8.5 

10.7 

13.5 

15.3 

19.3 

23.3 

28.4 

36.4 

45.1 

53.9 

62. 

70. 

32 

8.8 

11.1 

13.9 

15.8 

19.9 

24.1 

29.3 

37.6 

46.5 

55.6 

64. 

72.2 

33 

9.1 

11.4 

14.3 

16.3 

20.5 

24.8 

30.2 

38.8 

48. 

57.4 

66. 

74.4 

34 

9.4 

11.7 

14.7 

16.8 

21.2 

25.6 

31.1 

40. 

49.5 

59.1 

68. 

76.7 

35 

9.6 

12.1 

15.2 

17.3 

21.8 

26.3 

32. 

41.1 

50.9 

60.8 

70. 

79. 

36 

9.9 

12.5 

15.6 

17.8 

22.4 

27. 

33. 

42.3 

52.4 

62.6 

72. 

81.3 

37 

10.2 

12.8 

16.1 

18.3 

23. 

27.8 

33.9 

43.5 

53.8 

64.3 

74. 

83.5 

38 

10.5 

13.2 

16.5 

18.8 

23.7 

28.5 

34.8 

44.6 

55.2 

66. 

76. 

85.8 

39 

10.7 

13.5 

16.9 

19.3 

24.3 

29.3 

35.7 

45.8 

56.7 

67.8 

78. 

88. 

40 

11. 

13.8 

17.4 

19.8 

24.9 

30.1 

36.6 

47. 

58.2 

69.5 

80. 

90.2 

392 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


APPROXIMATE  SQUARE   FEET  OF  RADIATING   SURFACE   OF   PIPE    PER 
LINEAL    FOOT— Continued. 


fl* 

Diameter  of  Pipe. 

$* 

| 

l 

H 

11 

2 

2i 

3 

4 

5 

6 

7 

8 

41 

11   3 

14  ? 

17.8 

20.3 

25.5 

30.8 

37.6 

48.2 

59.6 

71.3 

82. 

92.5 

42 

11.5 

14.5 

18.2 

20.8 

26.1 

31.6 

38.5 

49.4 

61.1 

73. 

84. 

94.8 

43 

11.8 

14.9 

18.7 

21.3 

26.8 

32.3 

39.4 

50.6 

62.5 

74.8 

86. 

97. 

44 

12.1 

15.2 

19.1 

21.8 

27.4 

33.1 

40.3 

51.7 

64. 

76.5 

88. 

99.3 

45 

12.4 

15.6 

19.5 

22.2 

28. 

33.8 

41.2 

52.9 

65.5 

78.2 

90. 

101.6 

46 

12.7 

15.9 

20. 

22.7 

28.6 

34.6 

42.2 

54. 

67. 

80. 

92. 

103.8 

47 

12.9 

16.3 

20.4 

23.2 

29.2 

35.3 

43. 

55.2 

68.4 

81.7 

94. 

106. 

48 

13.2 

16.6 

20.8 

23.7 

29.9 

36.1 

43.9 

56.4 

69.8 

83.5 

96. 

108.4 

49 

13.5 

17. 

21.3 

24.2 

30.5 

36.8 

44.8 

57.6 

71.2 

85.1 

98. 

110.5 

50 

13.8 

17.3 

21.7 

24.7 

31.1 

37.6 

45.8 

58.7 

72.7 

87. 

100. 

112.8 

SINGLE-RIVETED  LAP-JOINT  WITH  INSIDE  COVER-PLATE. 

(1)  Resistance  to  tearing  between  outer  row  of  rivets  =  (P—d}tT. 

(2)  Resistance  to   tearing  between  inner  row    of    rivets    and 

shearing  outer  row  of  rivets  (P— 2d)tT+ —  S. 

(3)  Resistance  to  shearing  three  rivets  —j-S. 


(4)  Resistance  to  crushing  in  front  of  three  rivets  =  3tdC. 

(5)  Resistance  to  tearing  at  inner  row  of   rivets  and  crushing 
in  front  of  one  rivet  in  outer  row=  (p—2d)T  +  tdC. 


PIPE  AND  MISCELLANEOUS   DATA. 


393 


DOUBLE-RIVETED    LAP-JOINT   WITH    INSIDE   COVER-PLATE. 

(1)  Resistance  to  tearing  at  outer  row  of  rivets  =  (P—d)tT. 

(2)  Resistance  to  shearing  four  rivets  =  — j-$. 

(3)  Resistance  to  tearing  at  inner  row  and  shearing  outer  row 

7Q 

of  rivets=  (P-l^d)tT+~S. 


C 


(4)  Resistance  to  crushing  in  front  of  four  rivets  = 

(5)  Resistance  to  tearina;  at  inner  row  of  rivets  and  crushing 
in  front  of  one  rivet  =(P-lM)tT  +  tdC. 


Forms       o-f        Rivetirig 

2  D  - 


\60*  & 

HL  W//^,___j£2Z6&. 

'-  D  4\y\v\N 


A^^\^S\\H"D~- 


eD' 


^>  D^ 


C_7 


*  I.6D 

Hand  Snap          Machrne     Countersunk 

Riyetirjcj       Riv^t-incj.      F?iveting.      Riveting, 


394 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TENSILE   STRENGTH   OF   PLATE   PER  ONE   INCH   OF  WIDTH. 


Thickness  . 

Tensile  Strength  per  Square  Inch. 

50,000 

55,000 

60,000 

65,000 

70,000 

.& 

3125 

3437 

3750 

4062 

4375 

i 

6250 

6875 

.  7500 

8125 

8750 

1 

9375 

10312 

11250 

12187 

13125 

7 

12500 

13750 

15000 

16250 

17500 

ft 

15625 

17187 

18750 

20312 

21875 

1 

18750 

20625 

22500 

24375 

26250 

A 

21875 

24062 

26250 

28437 

30625 

* 

25000 

27500 

30000 

32500 

35000 

1 

28125. 

30937 

33750 

36562 

39375 

? 

31250 

34375 

37500 

40625 

43750 

tt 

34375 

37812 

41250 

44687 

48125 

1 

37500 

41250 

45000 

48750 

52500 

« 

40625 

44687 

48750 

52812 

56875 

I 

43750 

48125 

52500 

56875 

61250 

» 

46875 

51562 

56250 

60937 

65625 

50000 

55000 

60000 

65000 

70000 

SHEARING   STRENGTH   OF  RIVETS.     (SINGLE   SHEAR.) 


Shearing  Strength  per  Square  Inch. 

Diameter 

Area  of 

_* 

Rivet. 

section. 

30,000 

35,000 

40,000 

45,000 

50,000 

t 

0.1104 

3312 

3864 

4416 

4968 

5520 

0.1963 

5889 

6870 

7852 

8833 

9815 

| 

0.3068 

9204 

10738 

12272 

13806 

15340 

| 

0.4418 

13254 

15463 

17672 

19881 

22090 

£ 

0.6013 

18039 

21045 

24052 

27058 

30065 

1 

0.7854 

23562 

27489 

31416 

35343 

39270 

PIPE  AND  MISCELLANEOUS  DATA. 


395 


CRUSHING   STRENGTH   OF   RIVETS. 


The  crushing  strength  of  rivets  and  plates,  in  joints  that  fail 
by  crushing,  is  found  by  experiment  to  be  high  and  irregular. 
In  some  cases  it  has  amounted  to  150,000  Ibs.  per  square  inch; 
in  a  few  tests  it  has  been  less  than  85,000  Ibs.  per  square  inch.  A 
value  of  95,000  Ibs.  may  be  used  with  safety  for  general  calculations. 

DOUBLE-RIVETED    BUTT-JOINT. 

(1)  Resistance  to  tearing  at  outer  row  of  rivets  =  (P— d)tT. 

(2)  Resistance  to  shearing  two  rivets  in  double  shear  and  one 

57TG?2 

in  single  shear =— j— o. 

(3)  Resistance  to  tearing  at  inner  row  of  rivets  and  shearing 
one  of  the  outer  row  of  rivets=  (P-2d')tT+^—S, 


(4)  Resistance  to  crushing  in  front  of  three  rivets  =  3tdC. 

(5)  Crushing  in  front  of  two  rivets  and  shearing  one  rivet 


TRIPLE-RIVETED    BUTT-JOINT. 

(1)  Resistance  to  tearing  'at  outer  row  of  rivets  =  (P—  d)tF. 

(2)  Resistance  to  shearing  four  rivets  in  double  shear  and  one 

.      .     .     ,  9rrd2 

in  single  shear  =  ""T~~& 

(3)  Resistance  to  tearing  at  middle  row  of  rivets  and  shearing 
one  rivet=  (P 


396 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


(4)  Resistance  to  crushing  in  front  of  four  rivets  and  shearing 
one  rivet 


D    ©    ©    © 


(5)  Resistance  to  crushing  in  front  of  five  rivets  £dtC+dt<£!. 

FAILURE    OF  RIVETED   JOINTS. 

A  riveted  joint  may  fail  by  shearing  the  rivets,  tearing  the 
plate  between  the  rivets,  crushing  the  rivets  or  plate,  or  by  a 
combination  of  two  or  more  of  the  above  causes. 

To  determine  the  efficiency  of  a  riveted  joint,  calculate  the 
breaking  strength  by  the  different  ways  in  which  it  may  fail. 
That  method  of  failure  giving  the  least  result  will  show  the  actual 
strength  of  the  joint.  If  this  equals  $R,  and  S=  tensile  strength 

a 

of  the  solid  plate,  then  efficiency  = 


NOMENCLATURE. 


d= diameter  of  rivets; 
t= thickness  of  plate; 
tc=  thickness  of  cover-plates; 
p= pitch  of  inner  row  of  rivets; 
P=  pitch  of  outer  row  of  rivets; 
$=  shearing  strength  of  rivets; 
T=  tensile  strength  of  plate. 
C= crushing  strength  of  rivets. 


PIPE  AND  MISCELLANEOUS  DATA. 

SINGLE-RIVETED   LAP-JOINT. 


397 


(1)  Resistance  to  shearing  one  rivet  =  —7- 


(2) 
(3) 


tearing  plate  between  rivets=  (p—d)tT. 
crushing  of  rivet  or  plate  =  dtC. 


DOUBLE-RIVETED   LAP-JOINT. 


Staggered    Riveting 


Cham 

2nd2 
(1)  Resistance  to  shearing  two  rivets  =  r-j — S. 


(2) 
(3) 


'    tearing  between  two  rivets  =(p—d)tT. 
'    crushing  in  front  of  two  rivets  =  2dtC. 

MISCELLANEOUS  NOTES. 


To  Remove  Rust  from  Steel. — Steel  which  has  been  rusted 
can  be  cleaned  by  brushing  with  a  paste  compound  of  J  ounce 
cyanide  potassium,  %  ounce  Castile  soap,  1  ounce  whiting,  and 
water  sufficient  to  form  a  paste.  The  steel  should  be  washed 
with  a  solution  of  ^  ounce  cyanide  potassium  in  2  ounces  water. 

To  Preserve  Steel  from  Rust. — 1  part  caoutchouc,  16  parts 
turpentine.  Dissolve  with  a  gentle  heat,  then  add  8  parts  of 
boiled  oil.  Mix  by  bringing  them  to  the.  heat  of  boiling  water- 


398  AMERICAN  GAS-ENGINEERING  PRACTICE. 

apply  to  the  steel  with  a  brush,  in  the  way  of  varnish.  It  may 
be  removed  with  turpentine. 

To  Clean  Brass. — 1  part  roche  alum  and  16  parts  water. 
Mix.  The  articles  to  be  cleaned  must  be  made  warm,  then 
rubbed  with  the  above  mixture,  and  finished  with  fine  tripoli. 

Rust=joint  Cement. — (Quickly  setting.)  1  part  sal-ammoniac 
in  powder  (by  weight),  2  parts  flour  of  sulphur,  80  parts  iron  bor- 
ings, made  to  a  paste  with  water. 

(Slowly  setting.)  2  parts  sal-ammoniac,  1  part  flour  of  sulphur, 
200  parts  iron  borings.  The  latter  cement  is  the  best  if  the  joint 
is  not  required  for  immediate  use. 

Red=lead  Cement  for  Face  Joints. — 1  part  of  white  lead,  1 
part  of  red  lead,  mixed  with  linseed-oil  to  the  proper  consistency. 


SPEED    OF   SOUND. 

Feet  per 
Second. 

In  air,  at  zero  degrees 1093 

(Add  2  feet  for  each  degree  C.) 

In  water 4780 

In  copper 11666 

In  iron 16822 

Loads  on  Floors. — Floors  of  factories,  work-shops,  and  ware- 
houses should  be  able  to  carry  a  load  of  250  Ibs.  to  the  square  foot. 
Floors  of  large  buildings,  halls,  churches,  etc.,  should  be  able  to 
carry  150  Ibs.  per  square  foot,  while  those  of  dwellings  should 
carry  120  Ibs.  per  square  foot. 

ALLOWANCES   FOR   WIND    AND    SNOW. 

Lbs.  per 
Sq.  Ft. 

Weight  of  snow  on  horizontal  surface 15.5 

Wind  pressure  on  surface,  right  angle  to  line  of 

impact 24 . 6 

In  especially  exposed  places 31 

To  Test  White  Lead. — If  pure  carbonate  of  lead  will  not  lose 
weight  at  212°  F.,  68  grains  should  be  entirely  dissolved  in  150 
minims  of  acetic  acid  diluted  in  1  oz.  of  water. 


CONSUMPTION   OF   GAS   BY   GAS-ENGINES. 

Consumption  of  gas  by  gas-engines  ranges  from  18  to  24  feet 
of  gas  per  horse-power  hour. 


PIPE  AND  MISCELLANEOUS  DATA. 

TAP  DRILLS  FOR  "V"  THREADS. 


399 


Tap. 

Drill. 

Tap. 

Drill. 

Tap. 

Drill. 

#'—60 

55 

*"—  32 

40 

& 

"—  30 

29 

£'-44 

55 

V—  36 

38 

H 

"  —  32 

28 

iV'  —  72 

55 

I"—  40 

37 

ii 

"  —  36 

27 

No.  1   —56 

54 

\"—  44 

36 

M 

"—40 

27 

1   —60 

54 

No.  51  —30 

38 

No.  9 

—24 

29 

1   —64 

54 

5*  —32 

37 

9 

—28 

28 

1   —72 

54 

51  —36 

36 

9 

—30 

27 

11  —56 

52 

51  —40 

35 

9 

—32 

25 

11  —60 

52 

51  —44 

35 

9 

—36 

24 

11  —64 

52 

6   —30 

36 

9 

—40 

24 

11  —72 

51 

6   —32 

35 

91 

—24 

27 

£'  —  56 

52 

6   —36 

34 

9^ 

—28 

26 

&"  —  60 

52 

6   —40 

33 

91 

—30 

24 

&"—  64 

52 

^;;—  30 

35 

91 

—32 

23 

A"—  72 

51 

34 

0] 

—36 

22 

No.  2   —18 

50 

&"  —  36 

33 

91 

—40 

22 

2   —56 

49 

f"—  40 

32 

A 

"  24 

27 

2   —60 

49 

—30 

34 

"—28 

26 

2   —64 

48 

61  —32 

33 

A 

"—30 

24 

2*  —48 

47 

61  —36 

32 

"—32 

23 

21  —56 

46 

61  —40 

31 

A 

"  —  36 

22 

21  —60 

46 

7   —28 

33 

& 

"  —  40 

22 

&;;—  48 

47 

7   —30 

32 

No.  10 

—24 

27 

46 

7   —32 

32 

10 

—28 

26 

&"—  60 

46 

7   —36 

30 

10 

—30 

24 

No.  3   —40 

47 

7   —40 

29 

10 

—32 

23 

3   —48 

45 

71  —28 

32 

10 

—36 

22 

3   —56 

44 

71  —30 

31 

10 

—40 

22 

31  —40 

48 

71  —32 

30 

10} 

—24 

24 

31  —48 

46 

71  —36 

29 

w 

—28 

23 

31  —56 

45 

71  —40 

29 

10^ 

—30 

22 

&"—  32 

45 

&"—  28 

32 

loi 

—32 

21 

C~36 

44 

&"-30 

31 

101  —36 

20 

43 

&"—  32 

30 

101  —40 

20 

J--44 

43 

!&"—  36 

29 

11 

—24 

21 

42 

&"—  40 

29 

11 

—28 

20 

No.  4   —32 

45 

No.  8   —24 

31 

11 

—30 

19 

4   —36 

44 

8   —28 

30 

11 

—32 

18 

4   —40 

43 

8   —30 

30 

11 

—36 

17 

4   —44 

43 

8   —32 

29 

11 

—40 

17 

41  —32 

42 

8   —36 

28 

$ 

"  —  24 

21 

41  —36 

41 

8   —40 

28 

$ 

"—28 

20 

41  —40 

40 

81  —24 

30 

u 

"—30 

19 

41  —44 

40 

8   —28 

29 

"  —  32 

18 

5.  —30 

41 

8   —30 

29 

u 

"  —  36 

17 

5   —32 

40 

8   —32 

28 

if"—  40 

17 

5   —36 

39 

8   —36 

27 

No.  Ill  —24 

19 

5   —40 

38 

81  —40 

27 

11J 

—28 

18 

5   —44 

37 

ft"—  24 

30 

11J 

—30 

17 

t"—  30 

41 

tt"-28 

29 

11J 

—32 

16 

400  AMERICAN  GAS-ENGINEERING  PRACTICE. 

TAP  DRILLS  FOR  "V"   THREADS— Continued. 


Tap. 

Drill. 

Tap. 

Drill. 

Tap. 

Drill. 

No.  Hi  —36 

15 

No.  14 

—20 

9 

&"—  18 

2 

llj  —40 

15 

14 

—22 

9 

$2"  —  20 

1 

12 

—20 

18 

14 

—24 

8 

T&"  —  24 

1 

12 

—22 

17 

14 

—28 

8 

&"—  28 

H" 

12 

—24 

16 

14 

—30 

7 

&"—  30 

if 

12 

—28 

15 

14 

—32 

7 

No.  17  —16 

12 

—30 

15 

14 

—36 

6 

17  —18 

2 

12 

—32 

14 

14 

—40 

6 

17  —20 

1 

12 

—36 

13 

14, 

t  —20 

7 

17  —24 

1 

12 

—40 

13 

—22 

6 

17  —28 

H" 

j 

"—20 

20 

14; 

—24 

5 

17  —30 

c 

1 

"—22 

19 

14 

—28 

4 

18  —16 

"—24 

18 

14 

—30 

3 

18  —18 

1 

1 

"—28 

17 

14 

—32 

3 

18  —20 

if" 

1 

"—30 

16 

14J 

—36 

3 

18  —22 

B 

1 

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16 

14, 

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2 

18  —24 

B 

i 

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15 

j 

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7 

18  —28 

C 

i 

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15 

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6 

18  —30 

C 

No.  12, 

1^1 

r  —20 
—22 

16 
16 

I 

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5 
4 

19  —16 
19  —18 

f 

12i 

—24 

15 

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3 

19  —20 

G 

1^1 

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14 

1 

"  —  32 

3 

19  —24 

D 

12) 

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13 

| 

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2 

19  —30 

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12i 

—32 

12 

j 

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2 

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11 

No.  15 

—18 

8 

&"  —  -18 

f 

r  —40 

11 

15 

—20 

7 

T^  '  —  20 

\" 

13' 

—20 

14 

15 

—22 

6 

&"—  24 

F 

13 

—22 

14 

15 

—24 

5 

&"—  30 

F 

13 

—24 

13 

15 

—28 

4 

No.  20  —16 

C 

13 

—28 

12 

15 

—30 

3 

20  —18 

}" 

13 

—30 

11 

15^ 

—18 

6 

20  —20 

F 

13 

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10 

15J 

—20 

5 

20  —22 

F 

13 

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9 

15*  —22 

4 

20  —24 

G 

13 

—40 
"—20 

9 
10 

15£  —24 

15|  _98 

3 
2 

21  —16 
21  —18 

IF 

^ 

"  —  22 

10 

isJ 

—30 

2 

21  —20 

G 

H"—  24 

9 

H 

"—18 

6 

21  —22 

G 

"  28 

9 

H 

"—20 

5 

21  —24 

H 

H"—  30 

8 

H 

"  22 

4 

22  —16 

H 

"  32 

8 

H 

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3 

22  —18 

J 

^ 

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7 

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2 

22  —20 

t" 

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7 

11 

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2 

22  —22 

i 

No.  13*  —20 

10 

No.  16 

—16 

8 

22  —24 

it" 

13  1 

—22 

10 

16 

—18 

6 

23  —16 

j 

I3i 

1  —24 

9 

16 

—20 

5 

23  —18 

&" 

13; 

f  —28 

9 

16 

—22 

4 

23  —20 

L 

13i 

|  —30 

8 

16 

—24 

3 

23  —22 

M 

13i 

r  —32 

8 

16 

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2 

23  —24 

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7 

16 

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1 

24  —14 

L 

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7 

ft 

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4 

24  —16 

r 

UNIVERSIT 

OF 

ILIF< 


PIPE  AND  MISCELLANEOUS  DATA. 

TAP  DRILLS  FOR  "V"  THREADS— Continued. 


401 


Ta] 

3. 

Drill. 

Taj 

3. 

Drill. 

Tap. 

Drill. 

No.  24 

—18 

N 

No.  28 

—18 

8 

3"  12 

r 

24 
24 

—20 
—22 

Ao" 

28 
j 

—20 
-"—14 

H" 

H"—  10 

i"—  9 

24 

—24 

p 

1 

/'—  16 

H" 

I"—  10 

&' 

j 

'—14 

M 

1 

-"—18 

S" 

tt"—  9 

§i' 

'—16 

ft" 

3 

"—20 

r 

1"  —  7 

JL37 

'—18 

A" 

"—12 

1"  —  8 

t*; 

j 

'—20 

O 

1 

>"—  13 

2|" 

H"—  7 

j 

'—22 

P 

i 

/'—  14 

M;; 

1|"  —  8 

1" 

i 

'—24 

ft" 

j 

"—16 

H"—  7 

IA" 

No.  25 

—14 

ft" 

', 

"—18 

ft" 

H"—  8 

}< 

25 

—16 

A" 

\ 

"—20 

ft" 

1|"—  6 

25 

—18 

H" 

'—12 

M" 

H"—  6 

^ft" 

25 

—20 

ft" 

^ 

'—14 

H" 

if"—  5 

Jit" 

26 

—14 

A;; 

1 

'—10 

r 

If"—  5 

1  1?'' 

26 

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if"  —  4 

^A" 

26 

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Q 

j 

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M" 

if"  —  ^i 

^H" 

26 

—20 

c 

'—11 

A" 

2"  —  4 

144" 

28 

—14 

u 

'—12 

ft" 

2"  —  4| 

iii" 

28 

—  16 

s 

I 

"—10 

Mr/ 

USEFUL  INFORMATION. 

Water. — Doubling  the  diameter  of  a  pipe  increases  its  capacity 
four  times.  Friction  of  liquids  in  pipes  increases  as  the  square  of 
the  velocity. 

The  mean  pressure  of  the  atmosphere  is  usually  estimated 
at  14.7  Ibs.  per  square  inch,  so  that  with  a  perfect  vacuum  it  will 
sustain  a  column  of  mercury  29.9  inches  or  a  column  of  water 
33.9  feet  high  at  sea-level. 

To  find  the  pressure  in  pounds  per  square  inch  of  a  column  of 
water,  multiply  the  height  of  the  column  in  feet  by  .434.  Approxi- 
mately, we  say  that  every  foot  elevation  is  equal  to  J  Ib.  pressure 
per  square  inch;  this  allows  for  ordinary  friction. 

To  find  the  diameter  of  a  pump  cylinder  to  move  a  given  quan- 
tity of  water  per  minute  (100  feet  of  piston  being  the  standard 
of  speed),  divide  the  number  of  gallons  by  4,  then  extract  the 
square  root,  and  the  product  will  be  the  diameter  in  inches  of  the 
pump  cylinder. 

To  find  the  quantity  of  water  elevated  in  one  minute  running 
at  100  feet  of  piston  speed  per  minute,  square  the  diameter  of 
the  water  cylinder  in  inches  and  multiply  by  4.  Example :  Capacity 
of  a  5-inch  cylinder  is  desired.  The  square  of  the  diameter  (5  inches) 
is  25,  which,  multiplied  by  4,  gives  100,  the  number  of  gallons 
per  minute  (approximately). 


402 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


To  find  the  horse-power  necessary  to  elevate  water  to  a  given 
height,  multiply  the  weight  of  the  water  elevated  per  minute  in 
pounds  by  the  height  in  feet,  and  divide  the  product  by  33,000 
(an  allowance  should  be  added  for  water  friction,  and  a  further 
allowance  for  loss  in  steam  cylinder,  say  from  20  to  30  per  cent.). 

The  area  of  the  steam  piston,  multiplied  by  the  steam  pressure, 
gives  the  total  amount  of  pressure  that  can  be  exerted.  The  area 
of  the  water  piston,  multiplied  by  the  pressure  of  water  per  square 
inch,  gives  the  resistance.  A  margin  must  be  made  between  the 
power  and  the  resistance  to  move  the  pistons  at  the  required  speed — 
say  from  20  to  40  per  cent.,  according  to  speed  and  other  conditions. 

To  find  the  capacity  of  a  cylinder  hi  gallons:  Multiplying  the 
area  hi  inches  by  the  length  of  stroke  in  inches  will  give  the  total 
number  of  cubic  inches;  divide  this  amount  by  231  (which  is  the 
cubical  contents  of  a  U.  S.  gallon  in  inches),  and  the  product  is  the 
capacity  in  gallons. 

WEIGHT  AND   CAPACITY   OF  DIFFERENT  STANDARD  GALLONS    OF 

WATER. 


Cubic 
Inches 
in  a  Gallon. 

Weight  of  a 
Gallon  in 
Pounds. 

Gallons 
in  a 
Cubic  Foot. 

Weight  of  a  cubic 
foot  of  water,  English 

Imperial  or  English  . 
United  States  

277.274 
231.0 

10.00 
8.33111 

6.232102 
7.480519 

standard,  62.321  Ibs. 
avoirdupois 

Weight  of  crude  petroleum,  6J  Ibs.  per  U.  S.  gallon,  42  gal- 
lons to  the  barrel. 

Weight  of  refined  petroleum,  6J  Ibs.  per  U.  S.  gallon,  42  gal- 
lons to  the  barrel. 

A  "  miner's  inch  "  of  water  is  approximately  equal  to  a  supply 
of  12  U.  S.  gallons  per  minute. 

HANDY  RULE  FOR  FINDING    (APPROXIMATELY)   THE   CONTENTS    OF   A 
PIPE   IN   GALLONS   AND    CUBIC    FEET. 

Rule.  Multiply  the  square  of  the  diameter  of  the  pipe  in  inches 
by  the  length  in  yards,  and  divide  by  10  for  gallons  and  by  60 
for  cubic  feet. 

Example.  A  pipe  is  6  inches  diameter  and  400  yards  long;  what 
is  the  content? 


62X400-J- 10  =  1440  gallons. 
62X400-^60  =  240  cubic  feet. 


PIPE  AND  MISCELLANEOUS  DATA.  403 

CHEMICAL   EQUATIONS   FOR  COMBUSTION  IN   OXYGEN. 

Hydrogen,  H. 

2H2+O2=2H2O. 

Relation  by  volume  —  (2  vols.)  +  (1  vol.)  =  (2  vols.). 
"  weight   -1       +       8=9 

Carbon  monoxide,  CO. 

2CO+O2=2CO2. 


Relation  by  volume  —  (2  vols.)  +  (1  vol.)  =  2  vols. 
"  weight  7       +      4      =     11 

Olefiant  gas,  C2H4. 

C2H4+3O2=2CO2+2H20. 

Relation  by  volume  —  (1  vol.)  +  (3  vols.)  =  (2  vols.)  +  (2  vols.). 
"   weight  -      7      +      24      =      22      +       9 

Marsh-gas,  CH4. 

CH4+2O2=CO2+2H2O. 

Relation  by  volume  -  (1  vol.)  +  (2  vols.)  =  (1  vol.)  +  (2  vols.). 
"  weight   -      4       +      16      =      11     +        9 

1  cu.  ft.  of  hydrogen  at  32°  F.  and  14.7  Ibs.  per  sq.  in.  =  .00599 
lb.  To  find  the  weight  of  any  other  gas  per  cubic  foot,  multiply 
half  its  molecular  weight  by  .00599. 


CALORIFIC  POWERS  OF  FUELS  CALCULATED  FROM  ULTIMATE  ANALYSIS. 

Dulong's  formula: 

Heating  value  in  B.t.u.  =  ^[14,600  C  +62,000  (H-  ~)  +4050  SJ. 

Heating  value  in  calories =y^  [8140 C  +34,400 (H-^j +2250  S]. 

Mahler's  formula: 

Heating  value,  calories =T^ [8 140  C+34,500  H-3000(O+N)]. 
In  the  above  C  =  carbon,  H= hydrogen,  0= oxygen,  N= nitro- 
gen, S= sulphur. 


404 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


HEATS   OF   COMBUSTION   OF  VARIOUS   SUBSTANCES   IN   OXYGEN. 
(Favre  and  Silberman.) 


One  Part  by  Weight  of 

Burning  to 

Evolves 

Kilo-calories. 

B.t.u. 

Hydrogen 

H20  at  0°  C 
H2A  at  100°  C 
C00 
CO" 
CO2 
CO.,  and  H0O 
CO*  and  H,O 

34462 
28732 
8080 
2473 
2403 
13063 
11858 

62032 
51717 
14544 
4451 
4325 
23513 
21344 

Carbon  (wood  charcoal)  

i  ( 

Carbon  monoxide  

Marsh-gas 

Olefiant  gas  . 

HEATS  OF  COMBUSTION   OF  GASES   IN   OXYGEN. 
(By  Julius  Thompsen.) 


Heat-units 

Products  of 

Evolved. 

Kilo- 

Name. 

Sym- 
bol. 

at  18°  C. 

(64.4°  F.), 

Calories 

B.t.u. 

calories 
per 

B.t.u. 

cSbic 

Water 
Liquid. 

Kilo- 

per 
Pound 

Meter. 

Foot. 

of  Gas. 

of  Gas. 

Acetylene 

C,H, 

2CO2+  H2O 

11917 

21421 

13881 

1554 

Benzine  

C«H6 

6CO2+  2H2O 

10102 

18183 

35300 

3954 

Carbonic  oxide  

CO 

CO2 

2436 

4385 

3055 

342 

Ethane  

02H6 

:co2+  3H2o 

12420 

22356 

16692 

1870 

Ethylene  (olefiant  gas)  . 
Hydrogen  ...           .... 

A 

2CO2+  2H2O 
H2O 

11931 
34180 

21476 
61524 

14967 
3062 

1677 
344 

Methane  (marsh-gas)  .  . 

CH, 

CO2+  2H2O 

13320 

23976 

9548 

1070 

WEIGHT  AND   VOLUME   OF  GASES   AND   AIR   REQUIRED  IN  COMBUSTION. 


Name. 

Weght  per  Cubic 
Foot  in  Pounds 
at  32°  F.  and  14.7 
Pounds  per  Square 
Inch. 

Volume  in  Cubic 
Feet  of  1  Pound 
of  Gas  at  14.7 
Pounds  per  Square 
Inch. 

Cubic  Feet 
Required 
to  Burn 
1  Cubic  Foot 
of  Gas. 

Pounds  Re- 
quired to  Burn 
1  Pound  of 
the  Gas. 

Cubic 
Feet 
Formed 
of 

32°  F. 

62°  F. 

Oxy- 
gen. 

Air. 

Oxy- 
gen. 

Air. 

Steam. 

C02 

1 
0 

1 

2 

Air 

0.08073 
0.12300 
0.07830 
0.00599 
0.04470 
0.07830 
0.07830 
0.08940 

12.39 
8.12 
12.77 
178.80 
22.37 
12.77 
12.77 
11.20 

13.12 
8.60 
13.55 
189.80 
23.73 
13.55 
13.55 
11.88 

0.5 
0.5 
2.0 

3.0 

2.39 
2.39 
9.60 

14.4 

0.57 
8.00 
4.00 

3.43 

2.4B 
34.8 

17.4 

14.9 

0 

1 
2 

2 

Carbon  dioxide  . 
Carb.  monoxide 
Hydrogen  
Marsh-gas  
Nitrogen  .... 

Olefiant  gas  .  .  . 
Oxvsen  .  . 

Air  =  20.92  per  cent  of  oxygen. 


PIPE  AND  MISCELLANEOUS  DATA. 


405 


1  Ib.  carbon  burning  to  CO2  requires  11.6  Ibs.  of  air. 

1  "       "  "        "  Co         "          5.8  "    li   " 

Liquid  hydrocarbons  approximate  20,000  B.t.u.  per  Ib. 

Good  coal  approximates  14,000  B.t.u.  per  Ib. 

2J  Ibs.  of  dry  wood=l  Ib.  of  coal  or  .4  Ib.  coal=l  Ib.  wood. 


SPECIFIC  HEATS   OF  SUBSTANCES. 
SOLIDS  AND  LIQUIDS. 


Glass 

0  1937 

Coal.  .          0  20  to  0  24 

Cooper 

0  0951 

Cast  iron 

0  1298 

Coke.  .              .  .  0.203 

Charcoal  .  .  . 

0  2410 

Wrought  iron 

0  1138 

Brickwork  1              /-»  nf\ 

Mercury  .  .  . 

0  0333 

Steel  soft 

0.1165 

TUT                 >  .  .      .0.20 
Masonry     / 

Water  

1  0000 

Wood  0.46  to  0.65 

PRESSURES,  TEMPERATURE,   AND  VOLUME  OF  STEAM,   FROM  ATMOS- 
PHERIC  PRESSURE   TO   140   LBS.   PER  SQUARE   INCH. 


Lbs.  per 
Sq.  In. 

Temperature. 

Volume. 

Lbs.  per 
Sq.  In. 

Temperature. 

Volume. 

At.  pres. 

212.8 

1669 

34 

281.9 

564 

*1 

216.2 

1573 

40 

289.3 

508 

2 

219.6 

1488 

45 

295.5 

470 

3 

222.7 

1411 

50 

301.3 

437 

4 

225.6 

1343 

55 

306.4 

408 

5 

228.5 

1281 

60 

311.2 

383 

6 

231.2 

1225 

65 

315.8 

362 

7 

233.8 

1174 

70 

320.1 

342 

8 

236.3 

1127 

75 

324.3 

325 

9 

238.7 

1084 

80 

328.2 

310 

10 

241.0 

1044 

85 

332.0 

295 

12 

245.5 

973 

90 

335.8 

282 

14 

249.6 

911 

95 

339.2 

271 

16 

253.6 

857 

100 

342.7 

259 

18 

257.3 

810 

105 

345.8 

251 

20 

260.9 

767 

110 

349.1 

240 

22 

264.3 

729 

115 

352.1 

233 

24 

267.5 

569 

120 

355.0 

224 

26 

270.6 

664 

125 

357.9 

218 

28 

273.6 

635 

130 

360.6 

210 

30 

276.4 

610 

135 

363.4 

205 

32 

279.2 

586 

140 

366.0 

198 

*  These  are  boiler  pressures  (above  atmospheric),  as  shown  by  the  steam-gage.  The 
temperatures  are  Fahrenheit  scale.  The  volumes  given  represent  cubic  inches  of  steam 
for  every  cubic  inch  of  water  evaporated. 


406 


AMERICAN  GAS-ENGINEERING  PHACTICE. 


FRENCH 

One  milligramme  (0.001  of  a  gramme) 
One  centigramme  (0.01  of  a  gramme) 
One  decigramme  (0. 1  of  a  gramme) 
One  gramme  (unit  of  weight) 
One  decagramme  (10  grammes) 
One  hectogramme  (100  grammes) 
One  kilogramme  (1000  grammes) 
One  myriagramme  (10,000  grammes) 
One  quintal  (100,000  grammes) 
One  millier  (1,000,000  grammes) 
1016.0475443  kilogrammes 

0.45359265  kilogramme 
0.37324        kilogramme 


WEIGHTS. 


0.0154 
0.0000022 
0.1543 
0.0000220 
1.5432 
0.0002204 
15.4323 
0.0022046 
154.3234 

0.0220462 
1543.2348 

0.2204621 
15432.3487 

2.2046212 
154323.487 

22.0462124 
1543234.87 

220.462124 
15432348.7 

2204.62124 
15680000.0 
2204.0 

7000.0 

1.0 
5760.0 

1.0 


grains 

avoirdupois  Ibs. 
grains 

avoirdupois  Ibs. 
grains 

avoirdupois  Ibs. 
grains 

avoirdupois  Ibs. 
grains 

avoirdupois  Ibs. 
grains 

avoirdupois  Ibs. 
grains 

avoirdupois  Ibs. 
grains 

avoirdupois  Ibs. 
grains 

avoirdupois  Ibs. 
grains 

avoirdupois  Ibs. 
grains 
avoirdupois  Ibs. 

one  long  ton 
grains 

avoirdupois  Ibs. 
grains 
troy  pound 


TENSION   OF   MERCURY  VAPOR. 


Degrees 
Centigrade. 

Tension  in 
Millimeters. 

Degrees 
Centigrade. 

Tension  in 
Millimeters. 

Degrees 
Centigrade. 

Tension  in 
Millimeters. 

100 

0.75 

180 

11.00 

260 

96.73 

110 

1.07 

190 

14.84 

270 

123.01 

120 

1.53 

200 

19.90 

280 

155  .  17 

130 

2.18 

210 

26.35 

290 

194.46 

140 

3.06 

220 

34.70 

300 

242.15 

150 

4.27 

230 

45.35 

310 

299.69 

160 

5.90 

240 

58.82 

320 

368.73 

170 

8.09 

250 

75.75 

330 

450.91 

FRENCH  MEASURE. 


One  millimeter  (0.001  meter)  .............. 

One  centimeter  (0.01  meter) 

One  decimeter  (0.1  meter)  ................ 

One  meter  (unit  of  length)  ................ 

One  decameter  (10  meters)  ................ 

One  hectometer  (100  meters)  .............       3937  .043196 

One  kilometer  (1000  meters)  ..............     39370  .  431960 

One  myriameter  (10,000  meters)  ...........   393704.319600 

or  6  miles,  376  yards,  0  feet  and  8^  inches 


0.039370  inches 
0  .  393704      '  '    . 
3  .937043      " 
39  .  370432      " 
393  .  704320     " 


PIPE  AND  MISCELLANEOUS  DATA. 


407 


WHITWORTH'S  STANDARD  SCREW-THREADS  FOR  BOLTS,   WITH  SIZES 
OF  HEXAGONAL  NUTS   AND   BOLT-HEADS. 


Diameter  of  Bolt. 

Number 
of  Threads 
per  Inch. 

Diameter 
at  Bottom 
of  Thread. 

Distance 

Across 
Flats. 

Distance 
Across 
Corners. 

Thickness 
of  Bolt- 
head. 

Thickness 
of  Nut. 

Fractional 
Sizes. 

Decimal 
Sizes. 

Tif 

0.0625 

60 

0.0411 

0.212 

0.2447 

0.0547 

TS 

& 

0.09375 

48 

0.0670 

0.280 

0.3233 

0.0820 

& 

£ 

0.125 

40 

0.0929 

0.338 

0.3902 

0.1093 

* 

JL 

0.15625 

32 

0.1162 

0.3875 

0.4474 

0.1367 

:& 

0.1875 

24 

0.1341 

0.448 

0.5173 

0.1640 

A 

| 

0.25 

20 

0.1859 

0.525 

0.6062 

0.2187 

£ 

JL 

0.3125 

18 

0.2413 

0.6014 

0.6944 

0.2734 

JL 

3 

0.375 

16 

0.2949 

0.7094 

0.8191 

0.3281 

| 

0.4375 

14 

0.3460 

0.8204 

0.9473 

0.3828 

7 

0.5 

12 

0.3932 

0.9191 

1.0612 

0.4375 

T 

& 

0.5625 

12 

0.4557 

1.011 

1.1674 

0.4921 

& 

1 

0.625 

11 

0.5085 

1.101 

1.2713 

0.5468 

1 

u 

0.6875 

11 

0.5710 

1.2011 

1.3869 

0.6015 

ft 

! 

0.75 

10 

0.6219 

1.3012 

1.5024 

0.6562 

if 

0.8125 

10 

0.6844 

1.39 

1.6050 

0.7109 

1 

i 

0.875 

9 

0.7327 

1.4788 

1.7075 

0.7656 

1 

If 

0.9375 

9 

0.7952 

1.5745 

1.8180 

0.8203 

if 

1.0 

8 

0.8399 

1.6701 

1.9284 

0.875 

1 

« 

1.125 

7 

0.9420 

1.8605 

2  .  1483 

0.9843 

li 

if 

1.25 

7 

1.0670 

2.0483 

2.3651 

1.0937 

if 

if 

1.375 

6 

1.1615 

2.2146 

2.5571 

1.2031 

ii 

1.5 

6 

1.2865 

2.4134 

2.7867 

1.3125 

i; 

if 

1.625 

5 

1.3688 

2.5763 

2.9748 

1.4218 

if 

if 

1.75 

5 

1.4938 

2.7578 

3  .  1844 

1.5312 

li 

ii 

1.875 

4.5 

1.5904 

3.0183 

3.4852 

1.6406 

If 

2 

2.0 

4.5 

1.7154 

3.1491 

3.6362 

1.75 

2 

2i 

2.125 

4.5 

1.8404 

3.337 

3.8532 

1.8593 

2i 

2f 

2.25 

4 

1.9298 

3.546 

4.0945 

1.9687 

2* 

2f 

2.375 

4 

2.0548 

3.75 

4.3301 

2.0781 

2f 

21 

2.5 

4 

2  .  1798 

3.894 

4.4964 

2.1875 

21 

2f 

2.625 

4 

2.3048 

4.049 

4.6753 

2.2968 

2f 

2| 

2.75 

3.5 

2.3840 

4.181 

4.8278 

2.4062 

2| 

2£ 

2.875 

3.5 

2.5090 

4.3456 

5.0178 

2.5156 

2£ 

3 

3.0 

3.5 

2.6340 

4.531 

5.2319 

2.625 

3 

H 

3.125 

3.5 

2.7590 

4.69 

5.4155 

2.734 

3i 

31 

3.25 

3.25 

2.8559 

4.85 

5.6002 

2.843 

31 

3f 

3.375 

3.25 

2.9809 

5.01 

5.7850 

2.953 

3f 

31 

3.5 

3.25 

3.1059 

5.157 

5.9755 

3.062 

31 

408 


AMERICAN  GAS-ENGINEERING   PRACTICE. 


WHITWORTH'S  STANDARD   SCREW-THREADS   FOR  BOLTS,  WITH  SIZES  OF 
HEXAGONAL  NUTS  AND  BOLT-HEADS— Continued. 


Diameter  of  Bolt. 

Number 
of  Threads 

Diameter 
at  Bottom 

Distance 

Across 

Distance 
Across 

Thickness 
of  Bolt- 

Thickness 

Fractional 

Decimal 

per  Inch. 

of  Thread 

Flats. 

Corners. 

head. 

of  Nut. 

Sizes. 

Sizes. 

31 

3.625 

3.25 

3.2309 

5.362 

6.1915 

3.171 

3J 

3.75 

3 

3.3231 

5.55 

6.4085 

3.281 

3| 

3.875 

3 

3.4481 

5.75 

6  .  6395 

3.39 

4.0 

3 

3.5731 

5.95 

6.8704 

3.5 

4 

41 

4.125 

3 

3.6981 

6.162 

7.1152 

3.609 

41 

4J 

4.25 

2.875 

3.8045 

6.375 

7.3612 

3.718 

41 

4f 

4.375 

2.875 

3.9295 

6.6 

7.6210 

3.828 

4f 

8 

4.5 

2.875 

4.0545 

6.825 

7.8819 

3.937 

41 

if 

4.625 

2.875 

4.1795 

7  .  0625 

8  .  1550 

4.046 

4f 

4| 

4.75 

2.75 

4.2843 

7.3 

8.4293 

4.156 

4f 

41 

4.875 

2.75 

4.4093 

7.55 

8.7179 

4.265 

41 

5 

5.0 

2.75 

4.5343 

7.8 

9.0066 

4.375 

5 

51 

5  .  125 

2.75 

4.6593 

8.065 

9.3126 

4.484 

51 

5* 

5.25 

2.625 

4.7621 

8.35 

9.6417 

4.593 

5j 

5f 

5.375 

2.625 

4.8871 

8.6 

9.9304 

4.703 

51 

5£ 

5.5 

2.625 

5.0121 

8.85 

10.2190 

4.812 

5i 

H 

5.625 

2.625 

5.1371 

9.15 

10.5655 

4.921 

5f 

5§ 

5.75 

2.5 

5.2377 

9.45 

10.9119 

5.031 

51 

5.875 

2.5 

5.3627 

9.75 

11.2583 

5.140 

51 

6 

6.0 

2.5 

5.4877 

10.0 

11.5470 

5.25 

6 

The  tables  given  below  will  be  found  useful  in  heat  calcula- 
tions, and  although  not  minutely  accurate  are  sufficiently  so  for 
practical  work.  The  British  thermal  unit  (B.t.u.)  is  used,  and 
the  heat-energies  given  are  calculated  upon  the  assumption  of  62° 
F.  as  the  initial  temperature,  and  the  reduction  of  the  temperature 
of  the  products  of  combustion  to  the  same  point  as  the  standard  for 
the  computation  of  all  heat-energies: 

Air  by  weight  contains  23  parts  O,  77  parts  N. 

Air  by  volume  contains  21  parts  O,  79  parts  N. 

Air  consumed  in  combustion: 

1  pound  C  burned  to  CO  consumes  1.33  pounds  O,  with  4.46  N, 
making  5.79  air. 

1  pound  C  burned  to  C02  consumes  2.667  pounds  O,  with 
8.927  N,  making  11.594  air. 


PIPE  AND  MISCELLANEOUS  DATA.  409 

Heat-units  For  1  Lb.  '    For  1  Cu.  Ft. 

Developed  in  of  Combustible,      of  Combustible, 

Burning.  B.t.u.  B.t.u. 

CtoCO 4,400 

CtoCO2 14,500 

CO  to  CO2 4,325  319 

H  to  H20 62,000  327 

CH4  to  CO2  and  H20 23,500  1007 

C2H4  to  C02  and  H20 21,400  1593 

Of  course  hydrogen  is  usually  only  burned  to  steam,  and  the 
energy  in  this  case  at  62°  initial  and  212°  final  temperature  is 
52,000  heat-units,  or,  making  both  temperatures  212°,  about 
53,000  heat-units.  Many  writers  use  this  standard  for  hydrogen 
in  their  computations;  but  in  all  theoretical  calculations  hydrogen 
should  be  given  credit  for  the  energy  developed  when  the  products 
of  combustion  are  reduced  to  the  standard  temperature  and  the 
losses  computed  in  its  utilization  from  that  standard. 

Number  of  cubic  feet  in  one  pound  of  the  following  gases  at 
62°  F.  and  atmospheric  pressure: 

Air 13 . 14  cubic  feet  per  pound. 

N 13.50  "  "  "       " 

0 11.88  "  "  " 

H 189.70  "  "  " 

CO 13.55  "  "  "       " 

CO2 8.60  "  "  " 

CH4 23.32  "  "  " 

C2H4 13.46  "  "  "       " 

Specific  heat  of  hydrogen 3.4 

"         "     tl  all  other  gases  may  be 

taken  at 0.25 

The  terms  "heat-units  "  and  " specific  heat  "  are  not  well 
understood  by  many  people,  but  the  following  definitions  by  a 
well-known  authority  will  make  them  clear: 

Specific  heat  is  that  quantity  of  heat  required  to  raise  one 
pound  of  any  substance  one  degree  compared  with  that  required 
to  raise  the  temperature  of  an  equal  weight  of  water  one  degree. 
In  other  words,  in  writing  down  the  specific  heat  of  any  substance 
we  do  it  in  comparison  with  water.  That  is  to  say,  water  is  the 
unit  or  standard.  If  it  takes  three  and  four-tenths  times  as  much 
heat  to  raise  one  pound  of  hydrogen  one  degree  as  to  raise  one 
pound  of  water  one  degree,  we  say  the  specific  heat  of  hydrogen 
is  3.4.  Now  the  same  quantity  of  heat  that  will  raise  a  pound 
of  water  one  degree  will  raise  about  ten  pounds  of  iron  one  degree, 
so  we  say  the  specific  heat  of  iron  is  0.10,  or,  to  be  exact,  0.1098. 


410 


AMERICAN   GAS-ENGINEERING  PRACTICE. 


Wood  and  Coal  Fuel. — The  American  Society  of  Mechanical 
Engineers  in  their  rules  for  boiler  tests  allow  1  Ib.  of  wood  =  0.4  Ib. 
of  coal,  or  2£  Ibs.  of  wood=l  Ib.  of  coal.  Other  authorities  esti- 
mate 2 1  Ibs.  of  dry  wood=l  Ib.  of  good  coal.  One  pound  of 
any  wood  is  practically  equivalent  to  1  Ib.  of  any  other  kind  of  wood 
equally  dry. 

Lbs. 
Lbs.  Coal. 

1  cord  of  hickory  or  hard  maple  weighs 4500  =  2000 

1  cord  of  white  oak  weighs 3850  =  1711 

1  cord  of  beech,  red  oak,  or  black  oak  weighs 3250  =  1445 

1  cord  of  poplar,  chestnut,  or  elm  weighs 2350  =  1044 

1  cord  of  average  pine  weighs 2000  =  890 


COMPARISON   OF  THERMOMETER  SCALES. 


Centi- 
grade. 

Reau- 
mur. 

Fahren- 
heit. 

Centi- 
grade. 

Reau- 
mur. 

Fahren- 
heit. 

Centi- 
grade. 

Reau- 
mur. 

Fahren- 
heit. 

-30 

-24.0 

-22.0 

14 

11.2 

57.2 

58 

46.4 

136.4 

-28 

-22.4 

-18.4 

16 

12.8 

60.8 

60 

48.0 

140.0 

-26 

-20.8 

-14.8 

18 

14.4 

64.4 

62 

49.6 

143.6 

-24 

-19.2 

-11.2 

20 

16.0 

68.0 

64 

51.2 

147.2 

-22 

-17.6 

-  7.6 

22 

17.6 

71.6 

66 

52.8 

150.8 

-20 

-16.0 

-   4.0 

24 

19.2 

75.2 

68 

54.4 

154.4 

-18 

-14.4 

-   0.4 

26 

20.8 

78.8 

70 

56.0 

158.0 

-16 

-12.8 

3.2 

28 

22.4 

82.4 

72 

57.6 

161.6 

-14 

-11.2 

6.8 

30 

24.0 

86.0 

74 

59.2 

165.2 

-12 

-   9.6 

10.4 

32 

25.6 

89.6 

76 

60.8 

168.8 

-10 

-  8.0 

14.0 

34 

27.2 

93.2 

78 

62.4 

172.4 

-  8 

-  6.4 

17.6 

36 

28.8 

96.8 

80 

64.0 

176.0 

-  6 

-  4.8 

21.2 

38 

30.4 

100.4 

82 

65.6 

179.6 

-  4 

-   3.2 

24.8 

40 

32.0 

104.0 

84 

67.2 

183.2 

-   2 

-    1.6 

28.4 

42 

33.6 

107.6 

86 

68.8 

186.8 

0 

0,0 

32.0 

44 

35.2 

111.2 

88 

70.4 

190.4 

2 

1.6 

35.6 

46 

36.8 

114.8 

90 

72.0 

194.0 

4 

3.2 

39.2 

48 

38.4 

118.4 

92 

73.6 

197.6 

6 

4.8 

42.8 

50 

40.0 

122.0 

94 

75.2 

201.2 

8 

6.4 

46.4 

52 

41.6 

125.6 

96 

76.8 

204.8 

10 

8.0 

50.0 

54 

43.2 

129.2 

98 

78.4 

208.4 

12 

9.6 

53.6 

56 

44.8 

132.8 

100 

80.0 

212.0 

PIPE  AND  MISCELLANEOUS   DATA. 


411 


MULTIPLIERS  FOR  FINDING  THE  EQUIVALENT  RATE  OF  EVAPORATION 
OF  WATER  FROM  AND  AT  212°  F.,  FOR  GIVEN  PRESSURES  OF  STEAM 
AND  TEMPERATURES  OF  FEED-WATER. 


Temper- 
ature of 
Feed- 
water, 
0  Fahr. 

Boiler  Pressures  in  Pounds  per  Square  Inch  above  the  Atmosphere. 

0 

5 

10 

15 

20 

25 

30 

32 

1.187 

1.192 

1.195 

1.199 

1.201 

1.204 

1.206 

35 

1.184 

1.189 

.192 

1.196 

1.198 

1.201 

1.203 

40 

1.179 

1.184 

.187 

1.191 

1  .  193 

1.196 

1.198 

45 

1.173 

1.178 

.181 

1.185 

1.187 

1  .  190 

1.192 

50 

1.168 

1.173 

.177 

1.180 

1.182 

1.185 

1.187 

55 

1.163 

1.168 

.171 

1.175 

1.177 

1.180 

1.182 

60 

1.158 

1.163 

.166 

1.170 

1.172 

1.175 

1.177 

65 

1.153 

1.158 

1.161 

1.165 

1.167 

1.170 

1.172 

70 

1.148 

1.153 

1.156 

1.160 

1.162 

1.165 

1.167 

75 

1.143 

1.148 

1.151 

1.155 

1.157 

1.160 

1.162 

80 

1.137 

1.143 

.146 

1.149 

1.151 

1.154 

1.156 

85 

1.132 

1.137 

.140 

1.144 

1.146 

1.149 

1.151 

90 

1.127 

1.132 

.135 

1.139 

1.141 

1.144 

1.146 

95 

1.122 

1.127 

.130 

1.134 

1  .  136 

1.139 

1.141 

100 

1.117 

1.122 

.125 

1.129 

1.131 

1.134 

1.136 

105 

1.111 

1.117 

.120 

1.123 

1  .  125 

1.128 

1.130 

110 

1.106 

1.111 

.114 

1.118 

1.120 

1.123 

1.125 

115 

1.101 

1.106 

1.109 

1.113 

1.115 

1.118 

1.120 

120 

1.096 

1.101 

1.104 

1.108 

1.101 

1.113 

1.115 

125 

1.091 

1.096 

1.099 

1.103 

1.105 

1.108 

1.110 

130 

.085 

1.091 

1.094 

1.097 

1.099 

1.102 

1.104 

135 

.080 

1.085 

1.088 

1.092 

1.094 

1.097 

1.099 

140 

.075 

1.080 

1.083 

1.087 

1.089 

1.092 

1.094 

145 

.070 

1.075 

1.078 

1.082 

1.084 

1.087 

1.089 

150 

.065 

1.070 

1.073 

1.077 

1.079 

1.082 

1.084 

155 

.059 

1.065 

1.068 

1.071 

1.073 

1.076 

.078 

160 

.054 

.059 

.062 

1.066 

1.068 

1.071 

.073 

165 

1.049 

.054 

.057 

1.061 

1.063 

1.066 

.068 

170 

1.044 

.049 

.052 

1.056 

1.058 

1.061 

.063 

175 

1.039 

.044 

.047 

1.051 

1.053 

1.056 

.058 

180 

1.033 

.039 

.042 

1.045 

1.047 

1.050 

1.052 

185 

1.028 

.033 

.036 

1.040 

.042 

1.045 

1.047 

190 

1.023 

.028 

.031 

1.035 

.037 

1.040 

.042 

195 

1.018 

.023 

.025 

1.030 

.032 

1.035 

.037 

200 

1.013 

1.018 

.021 

1.025 

.027 

1.030 

.032 

205 

1.008 

1.013 

.015 

1.020 

.022 

1.025 

.027 

210 

1.008 

1.008 

.011 

1.015 

.017 

1.020 

.022 

212 

1.002 

1.002 

412 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


MULTIPLIERS  FOR  FINDING  THE  EQUIVALENT  RATE  OF  EVAPORATION 
OF  WATER  FROM  AND  AT  212°  F.,  FOR  GIVEN  PRESSURES  OF  STEAM 
AND  TEMPERATURES  OF  FEED-WATER— Continued. 


Temper- 
ature of 
Feed- 
Water, 
0  Fahr. 

Boiler  Pressures  in  Pounds  per  Square  Inch  above  the  Atmosphere. 

35 

40 

45 

50 

60 

70 

80 

32 

1.209 

1.211 

.212 

.214 

.217 

.219 

1.222 

35 

1.206 

1.208 

.209 

.211 

.214 

.216 

1.219 

40 

.201 

1.203 

.204 

.206 

.209 

.211 

1.214 

45 

.195 

1.197 

.198 

.200 

.203 

.205 

1.208 

50 

.190 

1.192 

.193 

.195 

.198 

.200 

1.203 

55 

.185 

1.187 

1.188 

1.190 

1.193 

.195 

1.198 

60 

.180 

1.182 

1.183 

1.185 

1.188 

.190 

1.193 

65 

1.175 

1.177 

1.178 

1.180 

1.183 

1.185 

1.188 

70 

1.170 

.172 

1.173 

1.175 

1.178 

1.180 

1.183 

75 

1.165 

.167 

1.168 

1.170 

1.173 

1.175 

1.178 

80 

1.159 

.161 

1.162 

1.164 

1.167 

1.169 

1.172 

85 

1.154 

.156 

1.157 

1.159 

1.162 

1.164 

1.167 

90 

1.149 

.151 

1.152 

1.154 

1.157 

.159 

1.162 

95 

1.144 

.146 

1.147 

1.149 

1.152 

.154 

1.157 

100 

1.139 

.141 

1.142 

1.144 

1.147 

.149 

1.152 

105 

1.133 

.135 

.136 

1.138 

1.141 

.143 

1.146 

110 

1.128 

.130 

.131 

1.133 

1.136 

.138 

1.141 

115 

1.123 

.125 

.126 

1  .  128 

1.131 

.133 

1.136 

120 

1.11-8 

.120 

.121 

.123 

.126 

1.128 

1.131 

125 

1.113 

.115 

.116 

.118 

.121 

1.123 

1.126 

130 

1.107 

.109 

.110 

.112 

.115 

1.117 

1.120 

135 

1.102 

.104 

.105 

.107 

.110 

1.112 

1.115 

140 

1.097 

.099 

.100 

.102 

.105 

.107 

1.110 

145 

.092 

.094 

.095 

.097 

.100 

1.102 

1.105 

150 

.078 

.089 

.090 

.092 

.095 

1.097 

1.100 

155 

.081 

.083 

.084 

1.086 

.089 

1.091 

1.094 

160 

.076 

.078 

.079 

1.081 

.084 

1.086 

1.089 

165 

1.071 

.073 

1.074 

1.076 

.079 

1.081 

1.084 

170 

1.066 

.068 

1.069 

1.071 

.074 

1.076 

1.079 

175 

1.061 

1  063 

1.064 

1.066 

.069 

1.071 

1.074 

180 

1.055 

1  057 

1.058 

1.060 

.063 

1.065 

1.068 

185 

1.050 

1.052 

1.053 

1.055 

.058 

1.060 

1.063 

190 

1.045 

1.047 

1.048 

1.050 

.053 

1.055 

1.058 

195 

1.040 

1.042 

1.043 

1.045 

.048 

1.050 

1.053 

200 

1.035 

1.037 

1.038 

1.040 

.043 

1.045 

1.048 

205 

1.030 

1.032 

1.033 

1.035 

1.038 

1.040 

1.043 

210 

1.025 

1.027 

1.028 

1.030 

1.033 

1.035 

1.038 

PIPE  AND  MISCELLANEOUS  DATA. 


413 


MULTIPLIERS  FOR  FINDING  THE  EQUIVALENT  RATE  OF  EVAPORATION 
OF  WATER  FROM  AND  AT  212°  F.,  FOR  GIVEN  PRESSURES  OF  STEAM 
AND  TEMPERATURES  OF  FEED- WATER— Continued. 


Temper- 
ature of 
Feed- 
water, 
°Fahr. 

Boiler  Pressures  in  Pounds  per  Square  Inch  above  the  Atmosphere. 

90 

100 

120 

140 

160 

180 

200 

32 

1.224 

1.227 

1.231 

1.234 

1.237 

1.239 

1.241 

35 

1.221 

1.224 

1.228 

1.231 

1.234 

1.236 

1.238 

40 

1.216 

1.219 

1.223 

1.226 

1.229 

1.231 

1.233 

45 

1.210 

1.213 

1.217 

1.220 

1.223 

1.225 

1.227 

50 

1.205 

1.208 

1.212 

1.215 

1.218 

1.220 

1.222 

55 

1.200 

1.203 

.207 

1.210 

1.213 

1.215 

1.217 

60 

1.195 

1.198 

.202 

1.205 

1.208 

1.210 

1.212 

65 

1.190 

1  .  193 

.197 

.200 

1.203 

1.205 

1.207 

70 

1.185 

.188 

.192 

.195 

1.198 

1.200 

1.202 

75 

1.180 

.183 

.187 

.190 

1.193 

1.195 

1.197 

80 

1.174 

.177 

.181 

.184 

1.187 

1.189 

1.191 

85 

1.169 

.172 

.176 

.179 

1.182 

1.184 

1.186 

90 

1.164 

.167 

1.171 

.174 

1.177 

1.179 

1.181 

95 

1.159 

.162 

1.166 

.169 

1.172 

1.174 

1.176 

100 

1.154 

1.157 

1.161 

.164 

1.167 

1.169 

1.171 

105 

1.148 

1.151 

1.155 

1.158 

1.161 

1.163 

1.165 

110 

1.143 

1.146 

1.150 

1.153 

1  .  156 

1.158 

1.160 

115 

1.138 

1.141 

1.145 

1.148 

1.151 

1.153 

1.155 

120 

1.133 

1.136 

1.140 

1.143 

1.146 

1.148 

1.150 

125 

1.128 

1.131 

1.135 

1.138 

1.141 

1.143 

1.145 

130 

1.122 

1.125 

1.129 

1  .  132 

1.135 

1.137 

1.139 

135 

1.117 

1.120 

1.124 

1.127 

1.130 

1.132 

1.134 

140 

1.112 

1.115 

1.119 

1.122 

1.125 

1.127 

1.129 

145 

1.107 

1.110 

1.114 

1.117 

1.120 

1.122 

1.124 

150 

1.102 

1.105 

1.109 

1.112 

1.115 

1.117 

1.119 

155 

1.096 

1.099 

1  .  103 

1.106 

1.109 

1.111 

1.113 

160 

1.091 

1.094 

1.098 

1.101 

1.104 

1.106 

1.108 

165 

1.086 

1.089 

1.093 

1.096 

1.099 

1.101 

1.103 

107 

1.081 

1.084 

1.088 

1.091 

1.094 

1.096 

1.098 

175 

1.076 

1.079 

1.083 

1.086 

1.089 

1.091 

1.093 

180 

1.070 

1.073 

1.077 

1.080 

1.083 

1.085 

1.087 

185 

1.065 

1.068 

1.072 

1.075 

1.078 

1.080 

1.082 

190 

1.060 

1.063 

1.067 

1.070 

1.073 

1.075 

1.077 

195 

1.055 

1.058 

1.062 

1.065 

1.068 

1.070 

1.072 

200 

1.050 

1.053 

1.057 

1.060 

1.063 

1.065 

1.067 

205 

1.045 

1.048 

1.052 

1.055 

1.058 

1.060 

1.062 

210 

1.040 

1.043 

1.047 

1.050 

1.053 

1.550 

1.057 

414  AMERICAN  GAS-ENGINEERING  PRACTICE. 


STANDARD    SPECIFICATIONS    FOR    CAST-IRON    PIPE 
AND  SPECIAL  CASTINGS. 

DESCRIPTION    OF    PIPES. 

SECTION  1.  The  pipes  shall  be  made  with  hub  and  spigot 
joints,  and  shall  accurately  conform  to  the  dimensions  given  in 
Tables  Nos.  1  and  2.  They  shall  be  straight  and  shall  be  true 
circles  in  section,  with  their  inner  and  outer  surfaces  concentric, 
and  shall  be  of  the  specified  dimensions  in  outside  diameter.  They 
shall  be  at  least  12  feet  in  length,  exclusive  of  socket.  For  pipes 
of  each  size  from  4-inch  to  24-inch,  inclusive,  there  shall  be  two 
standards  of  outside  diameter,  and  for  pipes  from  30-inch  to 
60-inch,  inclusive,  there  shall  be  four  standards  of  outside  diam- 
eter, as  shown  by  Table  No.  2. 

All  pipes  having  the  same  outside  diameter  shall  have  the 
same  inside  diameter  at  both  ends.  The  inside  diameter  of  the 
lighter  pipes  of  each  standard  outside  diameter  shall  be  gradu- 
ally increased  for  a  distance  of  about  6  inches  from  each  end  of 
the  pipe  so  as  to  obtain  the  required  standard  thickness  and  weight 
for  each  size  and  class  of  pipe. 

Pipes  whose  standard  thickness  and  weight  are  intermediate 
between  the  classes  in  Table  No.  2  shall  be  made  of  the  same 
outside  diameter  as  the  next  heavier  class.  Pipes  whose  standard 
thickness  and  weight  are  less  than  shown  by  Table  No.  2  shall 
be  made  of  the  same  outside  diameter  as  the  Class  A  pipes,  and 
pipes  whose  thickness  and  weight  are  more  than  shown  by  Table 
No.  2  shall  be  made  of  the  same  outside  diameter  as  the  Class  D 
pipes. 

For  pipes  4-inch  to  12-inch,  inclusive,  one  class  of  special 
castings  shall  be  furnished,  made  from  Class  D  pattern.  Those 
having  spigot  ends  shall  have  outside  diameters  of  spigot  ends 
midway  between  the  two  standards  of  outside  diameter  as  shown 
by  Table  No.  2,  and  shall  be  tapered  back  for  a  distance  of  6  inches. 
For  pipes  from  14-inch  to  24-inch,  inclusive,  two  classes  of  special 
castings  shall  be  furnished,  Class  B  special  castings  with  Classes  A 
and  B  pipes,  and  Class  D  special  castings  with  Classes  C  and  D 
pipes,  the  former  to  be  stamped  "  AB"  and  the  latter  to  be  stamped 
"CD".  For  pipes  30-inch  to  60-inch,  inclusive,  four  classes  of 
special  castings  shall  be  furnished,  one  for  each  class  of  pipe,  and 
shall  be  stamped  with  the  letter  of  the  class  to  which  they  belong. 


PIPE   AND  MISCELLANEOUS  DATA.  415 


ALLOWABLE   VARIATION   IN   DIAMETER  OF  PIPES  AND  SOCKETS. 

SECTION  2.  Especial  care  shall  be  taken  to  have  the  sockets 
of  the  required  size.  The  sockets  and  spigots  will  be  tested  by 
circular  gages,  and  no  pipe  will  be  received  which  is  defective 
in  joint  room  from  any  cause.  The  diameters  of  the  sockets  and 
the  outside  diameters  of  the  bead  ends  of  the  pipes  shall  not  vary 
from  the  standard  dimensions  by  more  than  *.06  of  an  inch  for 
pipes  16  inches  or  less  in  diameter;  .08  of  an  inch  for  18-inch, 
20-inch,  and  24-inch  pipes;  .10  of  an  inch  for  30-inch,  36-inch, 
and  42-inch  pipes;  .12  of  an  inch  for  48-inch,  and  .15  of  an  inch 
for  54-inch  and  60-inch  pipes. 


ALLOWABLE    VARIATION    IN    THICKNESS. 

SECTION  3.  For  pipes  whose  standard  thickness  is  less  than 
1  inch  the  thickness  of  metal  in  the  body  of  the  pipe  shall  not 
be  more  than  .08  of  an  inch  less  than  the  standard  thickness,  and 
for  pipes  whose  standard  thickness  is  1  inch  or  more,  the  varia- 
tion shall  not  exceed  .10  of  an  inch,  except  that  for  spaces  not 
exceeding  8  inches  in  length  in  any  direction,  variations  from  the 
standard  thickness  of  .02  of  an  inch  in  excess  of  the  allowance 
above  given  shall  be  permitted. 

For  special  castings  of  standard  patterns  a  variation  of  50 
per  cent,  greater  than  allowed  for  straight  pipe  shall  be  permitted. 


DEFECTIVE    SPIGOTS    MAY    BE    CUT. 

SECTION  4.  Defective  spigot  ends  on  pipes  12  inches  or  more 
in  diameter  may  be  cut  off  in  a  lathe  and  a  half-round  wrought- 
iron  band  shrunk  into  a  groove  cut  in  the  end  of  the  pipe.  Not 
more  than  12  per  cent,  of  the  total  number  of  accepted  pipes  of 
each  size  shall  be  cut  and  banded,  and  no  pipe  shall  be  banded 
which  is  less  than  11  feet  in  length,  exclusive  of  the  socket. 

In  case  the  length  of  a  pipe  differs  from  12  feet,  the  standard 
weight  of  the  pipe  given  in  Table  No.  2  shall  be  modified  in  accord- 
ance therewith. 

SPECIAL    CASTINGS. 

SECTION  5.  All  special  castings  shall  be  made  in  accordance 
with  the  cuts  and  the  dimensions  given  in  the  table  forming  a 
part  of  these  specifications. 

The  diameters  of  the  sockets  and  the  external  diameters  of 


416  AMERICAN  GAS-ENGINEERING  PRACTICE. 

the  bead  ends  of  the  special  castings  shall  not  vary  from  the  stand- 
ard dimensions  by  more  than  .12  of  an  inch  for  castings  16  inches 
or  less  in  diameter;  .15  of  an  inch  for  18-inch,  20-inch,  and  24-inch; 
.20  of  an  inch  for  30-inch,  36-inch,  and  42-inch,  and  .24  of  an 
inch  for  48-inch,  54-inch,  and  60-inch.  These  variations  apply 
only  to  special  castings  made  from  standard  patterns. 

The  flanges  on  all  manhole  castings  and  manhole  covers  shall 
be  faced  true  and  smooth,  and  drilled  to  receive  the  bolts  of  the 
sizes  given  in  the  tables.  The  manufacturer  shall  furnish  and 
deliver  all  bolts  for  bolting  on  the  manhole  covers,  the  bolts  to 
be  of  the  sizes  shown  on  plans  and  made  of  the  best  quality  of 
mild  steel,  with  hexagonal  heads  and  nuts  and  sound,  well-fitting 
threads. 

MARKINGS. 

SECTION  6.  Every  pipe  and  special  casting  shall  have  distinctly 
cast  upon  it  the  initials  of  the  maker's  name.  When  cast  espe- 
cially to  order,  each  pipe  and  special  casting  larger  than  4-inch 
may  also  have  cast  upon  it  figures  showing  the  year  in  which 
it  was  cast  and  a  number  signifying  the  order  in  point  of  time 
in  which  it  was  cast,  the  figures  denoting  the  year  being  above 
and  the  number  below,  thus: 

1901  1901  1901 

1  2  3 

etc.,  also  any  initials,  not  exceeding  four,  which  may  be  required 
by  the  purchaser.  The  letters  and  figures  shall  be  cast  on  the 
outside  and  shall  be  not  less  than  2  inches  in  length  and  J  of  an 
inch  in  relief  for  pipes  8  inches  in  diameter  and  larger.  For 
smaller  sizes  of  pipes  the  letters  may  be  1  inch  in  length.  The 
weight  and  the  class  letter  shall  be  conspicuously  painted  in  white 
on  the  inside  of  each  pipe  and  special  casting  after  the  coating 
has  become  hard. 

ALLOWABLE    PERCENTAGE    OF    VARIATION    IN    WEIGHT. 

SECTION  7.  No  pipe  shall  be  accepted  the  weight  of  which 
shall  be  less  than  the  standard  weight  by  more  than  5  per  cent, 
for  pipes  16  inches  or  less  in  diameter,  and  4  per  cent,  for  pipes 
more  than  16  inches  in  diameter,  and  no  excess  above  the  standard 
weight  of  more  than  the  given  percentages  for  the  several  sizes 
shall  be  paid  for.  The  total  weight  to  be  paid  for  shall  not  exceed 
for  each  size  and  class  of  pipe  received  the  sum  of  the  standard 
weights  of  the  same  number  of  pieces  of  the  given  size  and  class 
by  more  than  2  per  cent. 


PIPE  AND  MISCELLANEOUS  DATA.  417 

No  special  casting  shall  be  accepted  the  weight  of  which  shall 
be  less  than  the  standard  weight  by  more  than  10  per  cent,  for 
pipes  12  inches  or  less  in  diameter,  and  8  per  cent,  for  larger  sizes, 
except  that  curves,  Y  pieces,  and  breeches  pipe  may  be  12  per 
cent,  below  the  standard  weight,  and  no  excess  above  the  standard 
weight  of  more  than  the  above  percentages  for  the  several  sizes 
will  be  paid  for.  These  variations  apply  only  to  castings  made 
from  the  standard  patterns. 


QUALITY    OF   IRON. 

SECTION  8.  All  pipes  and  special  castings  shall  be  made  of 
cast  iron  of  good  quality,  and  of  such  character  as  shall  make 
the  metal  of  the  castings  strong,  tough,  and  of  even  grain,  and 
soft  enough  to  satisfactorily  admit  of  drilling  and  cutting.  The 
metal  shall  be  made  without  any  admixture  of  cinder  iron  or 
other  inferior  metal,  and  shall  be  remelted  in  a  cupola  or  air- 
furnace. 

TESTS    OF   MATERIAL. 

SECTION  9.  Specimen  bars  of  the  metal  used,  each  being 
26  inches  long  by  2  inches  wide  and  1  inch  thick,  shall  be  made 
without  charge  as  often  as  the  engineer  may  direct,  and,  in  default 
of  definite  instructions,  the  contractor  shall  make  and  test  at 
least  one  bar  from  each  heat  or  run  of  metal.  The  bars,  when 
placed  flatwise  upon  supports  24  inches  apart  and  loaded  in  the 
center,  shall  for  pipes  12  inches  or  less  in  diameter  support  a  load 
of  1900  pounds  and  show  a  deflection  of  not  less  than  .30  of  an 
inch  before  breaking,  and  for  pipes  of  sizes  larger  than  12  inches 
shall  support  a  load  of  2000  pounds  and  show  a  deflection  of  not 
less  than  .32  of  an  inch.  The  contractor  shall  have  the  right  to 
make  and  break  three  bars  from  each  heat  or  run  of  metal,  and 
the  test  shall  be  based  upon  the  average  results  of  the  three  bars. 
Should  the  dimensions  of  the  bars  differ  from  those  above  given, 
a  proper  allowance  therefor  shall  be  made  in  the  results  of  the 
tests. 

CASTING    OF    PIPES. 

SECTION  10.  The  straight  pipes  shall  be  cast  in  dry  sand 
molds  in  a  vertical  position.  Pipes  16  inches  or  less  in  diameter 
shall  be  cast  with  the  hub  end  up  or  down,  as  specified  in  the 
proposal.  Pipes  18  inches  or  more  in  diameter  shall  be  cast  with 
the  hub  end  down. 


418  AMERICAN  GAS-ENGINEERING  PRACTICE 

The  pipes  shall  not  be  stripped  or  taken  from  the  pit  while 
showing  color  of  heat,  but  shall  be  left  in  the  flasks  for  a  sufficient 
length  of  time  to  prevent  unequal  contraction  by  subsequent 
exposure. 

QUALITY    OP    CASTINGS. 

SECTION  11.  The  pipes  and  special  castings  shall  be  smooth, 
free  from  scales,  lumps,  blisters,  sand  holes,  and  defects  of  every 
nature  which  unfit  them  for  the  use  for  which  they  are  intended. 
No  plugging  or  filling  will  be  allowed. 

CLEANING    AND    INSPECTION. 

SECTION  12.  All  pipes  and  special  castings  shall  be  thoroughly 
cleaned  and  subjected  to  a  careful  hammer  inspection.  No  cast- 
ing shall  be  coated  unless  entirely  clean  and  free  from  rust,  and 
approved  in  these  respects  by  the  engineer  immediately  before 
being  dipped. 

COATING. 

SECTION  13.  Every  pipe  and  special  casting  shall  be  coated 
inside  and  out  with  coal-tar  pitch  varnish.  The  varnish  shall 
be  made  from  coal-tar.  To  this  material  sufficient  oil  shall  be 
added  to  make  a  smooth  coating,  tough  and  tenacious  when  cold, 
and  not  brittle  nor  with  any  tendency  to  scale  off. 

Each  casting  shall  be  heated  to  a  temperature  of  300  degrees 
Fahrenheit  immediately  before  it  is  dipped,  and  shall  possess 
less  than  this  temperature  at  the  time  it  is  put  in  the  vat.  The 
ovens  in  which  the  pipes  are  heated  shall  be  so  arranged  that  all 
portions  of  the  pipe  shall  be  heated  to  an  even  temperature.  Each 
casting  shall  remain  in  the  bath  at  least  five  minutes. 

The  varnish  shall  be  heated  to  a  temperature  of  300  degrees 
Fahrenheit  (or  less  if  the  engineer  shall  so  order),  and  shall  be 
maintained  at  this  temperature  during  the  time  the  casting  is 
immersed. 

Fresh  pitch  and  oil  shall  be  added  when  necessary  to  keep 
the  mixture  at  the  proper  consistency,  and  the  vat  shall  be  emptied 
of  its  contents  and  refilled  with  fresh  pitch  when  deemed  necessary 
by  the  engineer.  After  being  coated  the  pipes  shall  be  carefully 
drained  of  the  surplus  varnish.  Any  pipe  or  special  casting  that 
is  to  be  recoated  shall  first  be  thoroughly  scraped  and  cleaned. 


PIPE  AND  MISCELLANEOUS  DATA. 


419 


HYDROSTATIC    TEST. 

SECTION  14.  When  the  coating  has  become  hard,  the  straight 
pipes  shall  be  subjected  to  a  proof  by  hydrostatic  pressure  and, 
if  required  by  the  engineer,  they  shall  also  be  subjected  to  a  ham- 
mer test  under  this  pressure. 

The  pressures  to  which  the  different  sizes  and  classes  of  pipes 
shall  be  subjected  are  as  follows: 


20-inch  Diameter 
and  Larger, 
Lbs.  per  Sq.  In. 

Less  than  20- 
inch  Diameter 
Lbs.  per  Sq.  In. 

Class  A  pipe  

150 

300 

Class  B  pipe  

200 

300 

Class  C  pipe  

250 

300 

Class  D  pipe  

300 

300 

WEIGHING. 

SECTION  15.  The  pipes  and  special  castings  shall  be  weighed 
for  payment  under  the  supervision  of  the  engineer  after  the  appli- 
cation of  the  coal-tar  pitch  varnish.  If  desired  by  the  engineer, 
the  pipes  and  special  castings  shall  be  weighed  after  their  de- 
livery, and  the  weights  so  ascertained  shall  be  used  in  the  final 
settlement,  provided  such  weighing  is  done  by  a  legalized  weigh- 
master.  Bids  shall  be  submitted  and  a  final  settlement  made  up 
on  the  basis  of  a  ton  of  2000  pounds. 


CONTRACTOR  TO  FURNISH  MEN  AND  MATERIALS. 

SECTION  16.  The  contractor  shall  provide  all  tools,  testing- 
machines,  materials,  and  men  necessary  for  the  required  testing, 
inspection,  and  weighing  at  the  foundry  of  the  pipes  and  special 
castings;  and,  should  the  purchaser  have  no  inspector  at  the 
works,  the  contractor  shall,  if  required  by  the  engineer,  furnish 
a  sworn  statement  that  all  of  the  tests  have  been  made  as  specified, 
this  statement  to  contain  the  results  of  the  tests  upon  the  test- 
bars. 


POWER    OF    ENGINEER    TO    INSPECT. 

SECTION  17.  The  engineer  shall  be  at  liberty  at  all  times   to 
inspect  the  material   at  the  foundry,  and  the  molding,  casting, 


420  AMERICAN  GAS-ENGINEERING  PRACTICE. 

and  coating  of  the  pipes  and  special  castings.  The  forms,  sizes, 
uniformity,  and  conditions  of  all  pipes  and  other  castings  herein 
referred  to  shall  be  subject  to  his  inspection  and  approval,  and 
he  may  reject,  without  proving,  any  pipe  or  other  casting  which 
is  not  in  conformity  with  the  specifications  or  drawings. 


INSPECTOR    TO    REPORT. 

SECTION  18.  The  inspector  at  the  foundry  shall  report  daily 
to  the  foundry  office  all  pipes  and  special  castings  rejected,  with 
the  causes  for  rejection. 


CASTINGS    TO    BE    DELIVERED    SOUND    AND    PERFECT. 

SECTION  19.  All  the  pipes  and  other  castings  must  be  delivered 
in  all  respects  sound  and  conformable  to  these  specifications. 
The  inspection  shall  not  relieve  the  contractor  of  any  of  his  obli- 
gations in  this  respect,  and  any  defective  pipe  or  other  castings 
which  may  have  passed  the  engineer  at  the  works  or  elsewhere 
shall  be  at  all*  times  liable  to  rejection  when  discovered,  until  the 
final  completion  and  adjustment  of  the  contract;  provided,  how- 
ever, that  the  contractor  shall  not  be  held  liable  for  pipes  or  special 
castings  found  to  be  cracked  after  they  have  been  accepted  at 
the  agreed  point  of  delivery.  Care  shall  be  taken  in  handling 
the  pipes  not  to  injure  the  coating,  and  no  pipes  or  other  mate- 
rial of  any  kind  shall  be  placed  in  the  pipes  during  transporta- 
tion or  at  any  time  after  they  receive  the  coating. 


DEFINITION    OF    THE    WORD 

SECTION  20.  Wherever  the  word  " engineer"  is  used  herein  it 
shall  be  understood  to  refer  to  the  engineer  or  inspector  acting 
for  the  purchaser  and  to  his  properly  authorized  agents,  limited 
by  the  particular  duties  intrusted  to  them. 


STANDARD  PIPE   SPECIALS. 

The  following  sections,  dimensions,  and  weights  of  cast-iron 
pipe  specials  were  adopted  by  the  American  Gaslight  Association 
before  it  was  merged  into  the  American  Gas  Institute.  They  are 
the  result  of  years  of  consideration  and  pretty  well  represent  the 
average  gas  company  requirements. 


PIPE  AND  MISCELLANEOUS  DATA. 


421 


TABLE  NO.  1.— GENERAL  DIMENSIONS  OF  PIPES. 


Nomi- 
nal 
Diam- 
eter, 
Inches. 

Classes. 

Actual 
Outside 
Diam- 
eter, 
Inches. 

Diameter  of 
Sockets. 

Depth  of 
Sockets. 

A 

B 

C 

Pipe, 
Inches. 

Special 
Castings, 
Inches. 

Pipe, 
Inches. 

Special 
Cast- 
ings, 
Inches. 

4 

A-B 

4.80 

5.60 

5.70 

3.50 

4.00 

1.5 

1.30 

0.65 

4 

C-D 

5.00 

5.80 

5.70 

3.50 

4.00 

1.5 

1.30 

0.65 

6 

A-B 

6.90 

7.70 

7.80 

3.50 

4.00 

1.5 

1.40 

0.70 

6 

C-D 

7.10 

7.90 

7.80 

3.50 

4.00 

1.5 

1.40 

0.70 

8 

9.05 

9.85 

10.00 

4.00 

4.00 

1.5 

1.50 

0.75 

8 

'c-b' 

9.30 

10.10 

10.00 

4.00 

4.00 

1.5 

1.50 

0.75 

10 

A-B 

11.10 

11.90 

12.10 

4.00 

4.00 

1.5 

1.50 

0.75 

10 

C-D 

11.40 

12.20 

12.10 

4.00 

4.00 

1.5 

1.60 

0.80 

12 

A-B 

13.20 

14.00 

14.20 

4.00 

4.00 

1.5 

1.60 

0.80 

12 

C-D 

13.50 

14.30 

14.20 

4.00 

4.00 

1.5 

1.70 

0.85 

14 

A-B 

15.30 

16.10 

16.10 

4.00 

4.00 

1.5 

1.70 

0.85 

14 

C-D 

15.65 

16.45 

16.45 

4.00 

4.00 

1.5 

1.80 

0.90 

16 

A-B 

17.40 

18.40 

18.40 

4.00 

4.00 

1.75 

1.80 

0.90 

16 

C- 

17.80 

18.80 

18.80 

4.00 

4.00 

1.75 

1.90 

1.00 

18 

A-B 

19.50 

20.50 

20.50 

4.00 

4.00 

1.75 

1.90 

0.95 

18 

C-D 

19.92 

20.92 

20.92 

4.00 

4.00 

1.75 

2.10 

1.05 

20 

A-B 

21.60 

22.60 

22.60 

4.00 

4.00 

1.75 

2.00 

1.00 

20 

C-D 

22.06 

23.06 

23.06 

4.00 

4.00 

1.75 

2.30 

1.15 

24 

A-B 

25.80 

26.80 

26.80 

4.00 

4.00' 

2.00 

2.10 

1.05 

24 

C-D 

26.32 

27.32 

27.32 

4.00 

4.00 

2.00 

2.50 

1.25 

30 

A 

31.74 

32.74 

32.74 

4.50 

4.50 

2.00 

2.30 

1.15 

30 

B 

32.00 

33.00 

33.00 

4.50 

4.50 

2.00 

2.30 

1.15 

30 

C 

32.40 

33.40 

33.40 

4.50 

4.50 

2.00 

2.60 

1.32 

30 

D 

32.74 

33.74 

33.74 

4.50 

4.50 

2.00 

3.00 

1.50 

422  AMERICAN  GAS-ENGINEERING  PRACTICE. 

TABLE   NO.  1— Continued. 


Diameter  of 

Depth  of 

Nomi- 

Actual 

Sockets. 

Sockets. 

nal 

Outside 

Diam- 

Classes. 

Diam- 

A 

B 

C 

eter, 
Inches. 

eter, 
Inches. 

Pipe, 

Special 

Pipe, 

Special 
Cast- 

Inches. 

Castings, 
Inches. 

Inches. 

T  inP' 
Inches. 

36 

A 

37.96 

38.96 

38.96 

4.50 

4.50 

2.00 

2.50 

.25 

36 

B 

38.30 

39.30 

39.30 

4.50 

4.50 

2.00 

2.80 

.40 

36 

C 

38.70 

39.70 

39.70 

4.50 

4.50 

2.00 

3.10 

.60 

36 

D 

39.16 

40.16 

40.16 

4.50 

4.50 

2.00 

3.40 

.80 

42 

A 

44.20 

45.20 

45.20 

5.00 

5.00 

2.00 

2.80 

.40 

42 

B 

44.50 

45.50 

45.50 

5.00 

5.00 

2.00 

3.00 

.50 

42 

C 

45.10 

46.10 

46.10 

5.00 

5.00 

2.00 

3.40 

.75 

42 

D 

45.58 

46.58 

46.58 

5.00 

5.00 

2.00 

3.80 

1.95 

48 

A 

50.50 

51.50 

51.50 

5.00 

5.00 

2.00 

3.00 

1.50 

48 

B 

50.80 

51.80 

51.80 

5.00 

5.00 

2.00 

3.30 

1.65 

48 

C 

51.40 

52.40 

52.40 

5.00 

5.00 

2.00 

3.80 

1.95 

48 

.  D 

51.98 

52.98 

52.98 

5.00 

5.00 

2.00 

4.20 

2.20 

54 

A 

56.66 

57.66 

57.66 

5.50 

5.50 

2.25 

3.20 

1.60 

54 

B 

57.10 

58.10 

58.10 

5.50 

5.50 

2.25 

3.60 

1.80 

54 

C 

57.80 

58.80 

58.80 

5.50 

5.50 

2.25 

4.00 

2.15 

54 

D 

58.40 

59.40 

59.40 

5.50 

5.50 

2.25 

4.40 

2.45 

60 

A 

62.80 

63.80 

63.80 

5.50 

5.50 

2.25 

3.40 

1.70 

60 

.  B 

63.40 

64.40 

64.40 

5.50 

5.50 

2.25 

3.70 

1.90 

60 

C 

64.20 

65.20 

65.20 

5.50 

5.50 

2.25 

4.20 

2.25 

60 

D 

64.82 

65.82 

85.62 

5.50 

5.50 

2.25 

4.70 

2.60 

PIPE  AND  MISCELLANEOUS  DATA.  423 

TABLE  NO.  2.— STANDARD  THICKNESSES  AND  WEIGHTS  OF  CAST-IRON  PIPE. 


T        •  J 

Class  A, 
100  Ft.  Head,  43  Lbs.  Pressure. 

Class  B, 
200  Ft.  Head,  86  Lbs.  Pressure. 

inside 
Diameter, 
Inches. 

Thick- 

Weight  per 

Thick- 

Weight  per 

Inches. 

Inches. 

Foot. 

Length. 

Foot. 

Length. 

4 

0.40 

20.0 

240 

0.45 

21.7 

260 

6 

0.44 

30.8 

370 

0.48 

33.3 

400 

8 

0.46 

42.9 

515 

0.51 

47.5 

570 

10 

0.50 

57.1 

685 

0.57 

63.8 

765 

12 

0.54 

72.5 

870 

0.62 

82.1 

985 

14 

0.57 

89.6 

1075 

0.66 

102.5 

1230 

16 

0.60 

108.3 

1300 

0.70 

125.0 

1500 

18 

0.64 

129.2 

1550 

0.75 

150.0 

1800 

20 

0.67 

150.0 

1800 

0.80 

175.0 

2100 

24 

0.76 

204.2 

2450 

0.89 

233.3 

2800 

30 

0.88 

291.7 

3500 

1.03 

333.3 

4000 

36 

0.99 

391.7 

4700 

1.15 

454.2 

545.0 

42 

1.10 

512.5 

6150 

1.28 

591.7 

7100 

48 

1.26 

666.7 

8000 

1.42 

750.0 

9000 

54 

1.35 

800.0 

9600 

1.55 

933.3 

11200 

60 

1.39 

916.7 

11000 

1.67 

1104.2 

13250 

Class  C, 

Class  D, 

300  Ft.  Head,  130  Lbs.  Pressure. 

400  Ft.  Head,  173  Lbs.  Pressure. 

Inside 
Diameter, 
Inches. 

Thick- 

Weight  per 

Thick- 

Weight  per 

ness, 
Inches. 

n6ss, 
Inches. 

Foot. 

Length. 

Foot. 

Length. 

4 

0.48 

23.3 

280 

0.52 

25.0 

300 

6 

0.51 

35.8 

430 

0.55 

38.3 

460 

8 

0.56 

52.1 

625 

0.60 

55.8 

670 

10 

0.62 

70.8 

850 

0.68 

76.7 

920 

12 

0.68 

91.7 

1100 

0.75 

100.0 

1200 

14 

0.74 

116.7 

1400 

0.82 

129.2 

1550 

16 

0.80 

143.8 

1725 

0.89 

158.3 

1900 

18 

0.87 

175.0 

2100 

0.96 

191.7 

2300 

20 

0.92 

208.3 

2500 

1.03 

229.2 

2750 

24 

1.04 

279.2 

3350 

1.16 

306.7 

3680 

30 

1.20 

400.0 

4800 

1.37 

450.0 

5400 

36 

1.36 

545.8 

6550 

1.58 

625.0 

7500 

42 

1.54 

716.7 

8600 

1.78 

825.0 

9900 

48 

1.71 

908.3 

10900 

1.96 

1050.0 

12600 

54 

1.90 

1141.7 

13700 

2.23 

1341.7 

16100 

60 

2.00 

1341.7 

16100 

2.38 

1583.3 

19000 

The  above  weights  are  for  12-feet  laying  lengths  and  standard  sockets;    proportionate 
allowance  to  be  made  for  any  variation  therefrom. 


424 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE  NO.  3.— ONE-QUARTER  CURVES. 
(Dimensions  in  Inches.) 


Nominal 
Diameter. 

Class. 

T 

R 

K 

S 

4 

D 

0.52 

16 

22.6 

8 

6 

D 

0.55 

16 

22.6 

8 

8 

D 

0.60 

16 

22.6 

10 

10 

D 

0.68 

16 

22.6 

12 

12 

D 

0.75 

16 

22.6 

12 

14 

A-B 

0.66 

18 

25.5 

12 

14 

C-D 

0.82 

18 

25.5 

12 

16 

A-B 

0.70 

24 

34. 

12 

16 

C-D 

0.89 

24 

34. 

12 

18 

A-B 

0.75 

24 

34. 

12 

18 

C-D 

0.96 

24 

34. 

12 

20 

A-B 

0.80 

24 

34. 

12 

20 

C-D 

1.03 

24 

34. 

12 

24 

A-B 

0.89 

30 

42.4 

12 

24 

C-D 

1.16 

30 

42.4 

12 

30 

A 

0.88 

36 

50.9 

12 

30 

B 

1.03 

36 

50.9 

12 

30 

C 

1.20 

36 

50.9 

12 

30 

D 

1.37 

36 

50.9 

12 

36 

A 

0.99 

48 

67.9 

12 

36 

B 

1.15 

48 

67.9 

12 

36 

C 

1.36 

48 

67.9 

12 

36 

D 

1.58 

48 

67.9 

12 

42 

A 

1.10 

48 

67.9 

12 

42 

B 

1.28 

48 

67.9 

12 

42 

C 

1.54 

48 

67.9 

12 

42 

D 

1.78 

48 

67.9 

12 

48 

A 

1.26 

48 

67.9 

12 

48 

B 

.42 

48 

67.9 

12 

48 

C 

.71 

48 

67.9 

12 

48 

D 

.96 

48 

67.9 

12 

54 

A 

.35 

54 

76.36 

12 

54 

B 

.55 

54 

76.36 

12 

54 

C 

.90 

54 

76.36 

12 

54 

D 

.23 

54 

76.36 

12 

60 

A 

.39 

60 

84.85 

12 

60 

B 

.67 

60 

84.85 

12 

60 

C 

2.00 

60 

84.85 

12 

60 

D 

2.38 

60 

84.85 

12 

PIPE  AND  MISCELLANEOUS  DATA. 


425 


TABLE   NO.  4— ONE-EIGHTH   AND   ONE-SIXTEENTH   CURVES. 
(Dimensions  in  Inches.) 


Nominal 
Diameter. 

Class. 

T 

One-eighth  Curves. 

One-sixteenth  Curves. 

R 

K 

s 

R 

K 

4 

D 

0.52 

24 

18.4 

4 

48 

18.7 

6 

D 

0.55 

24 

18.4 

4 

48 

18.7 

8 

D 

0.60 

24 

18.4 

4 

48 

18.7 

10 

D 

0.68 

24 

18.4 

4 

48 

18.7 

12 

D 

0.75 

24 

18.4 

4 

48 

18.7 

14 

A-B 

0.66 

36 

27.6 

72 

28.1 

14 

O-D 

0.82 

36 

27.6 

72 

28.1 

16 

A-B 

0.70 

36 

27.6 

72 

28.1 

16 

C-D 

0.89 

36 

27.6 

72 

28.1 

18 

A-B 

0.75 

36 

27.6 

72 

28.1 

18 

C-D 

0.96 

36 

27.6 

72 

28.1 

20 

A-B 

0.80 

48 

36.7 

96 

37.5 

20 

C-D 

1.03 

48 

36.7 

96 

37.5 

24 

A-B 

0.89 

60 

45.9 

120 

46.8 

24 

C-D 

1.16 

60 

45.9 

120 

46.8 

30 

A 

0.88 

60 

45.9 

120 

46.8 

30 

B 

1.03 

60 

45.9 

120 

46.8 

30 

C 

1.20 

60 

45.9 

• 

120 

46.8 

30 

D 

1.37 

60 

45.9 

120 

46.8 

36 

A 

0.99 

90 

68.9 

180 

70.2 

36 

B 

1.15 

90 

68.9 

180 

70.2 

36 

C 

1.36 

90 

68.9 

180 

70.2 

36 

D 

1.58 

90 

68.9 

180 

70.2 

42 

A 

1.10 

90 

68.9 

180 

70.2 

42 

B 

1.28 

90 

68.9 

180 

70.2 

42 

C 

1.54 

90 

68.9 

180 

70.2 

42 

D 

1.78 

90 

68.9 

180 

70.2 

48 

A 

1.26 

90 

68.9 

180 

70.2 

48 

B 

.42 

90 

68.9 

180 

70.2 

48 

C 

.71 

90 

68.9 

180 

70.2 

48 

D 

.96 

90 

68.9 

180 

70.2 

54 

A 

.35 

90 

68.9 

180 

70.2 

54 

B 

.55 

90 

68.9 

180 

70.2 

54 

C 

1.90 

90 

68.9 

180 

70.2 

54 

D 

2.23 

90 

68.9 

180 

70.2 

60 

A 

1.39 

90 

68.9 

180 

70.2 

60 

B 

1.67 

90 

68.9 

180 

70.2 

60 

C 

2.00 

90 

68.9 

180 

70.2 

60 

D 

2.38 

90 

68.9 

•• 

180 

70.2 

426 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE   NO.  5.— ONE-THIRTY-SECOND   AND   ONE-SIXTY-FOURTH  CURVES. 
(Dimensions  in  Inches.) 


Nominal 
Diameter. 

Class. 

T 

One-thi  rt  y-second 
Curves. 

One-sixty-fourth 
Curves. 

R 

K 

R 

K 

20 

A-B 

0.80 

240 

47.05 

480 

47.10 

20 

C-D 

1.03 

240 

47.05 

480 

47.10 

24 

A-B 

0.89 

240 

47.05 

480 

47.10 

24 

C-D 

1.16 

240 

47.05 

480 

47.10 

30 

A 

0.88 

240 

47.05 

480 

47.10 

30 

B 

.03 

240 

47.05 

480 

47.10 

30 

C 

.20 

240 

47.05 

480 

47.10 

30 

D 

.37 

240 

47.05 

480 

47.10 

36 

A 

0.99 

240 

47.05 

480 

47.10 

36 

B 

.15 

240 

47.05 

480 

47.10 

36 

C 

.36 

240 

47.05 

480 

47.10 

36 

D 

.58 

240 

47.05 

480 

47.10 

42 

A 

.10 

240 

47.05 

480 

47.10 

42 

B 

1.28 

240 

47.05 

480 

47.10 

42 

C 

1.54 

240 

47.05 

480 

47.10 

42 

D 

1.78 

240 

47.05 

480 

47.10 

48 

A 

1.26 

240 

47.05 

480 

47.10 

48 

B 

.42 

240 

47.05 

480 

47.10 

48 

C 

.71 

240 

47.05 

480 

47.10 

48 

D 

.96 

240 

47.05 

480 

47.10 

54 

A 

.35 

240 

47.05 

480 

47.10 

54 

B 

.55 

240 

47.05 

480 

47.10 

54 

C 

.90 

240 

47.05 

480 

47.10 

54 

D 

.23 

240 

47.05 

480 

47.10 

60 

A 

.39 

240 

47.05 

480 

47.10 

60 

B 

.67 

240 

47.05 

480 

47.10 

60 

C 

2.00 

240 

47.05 

480 

47.10 

60 

D 

2.38 

240 

47.05 

480 

47.10 

PIPE  AND  MISCELLANEOUS  DATA. 


427 


TABLE   NO.  6.— BRANCHES. 
(Dimensions  in  Inches.) 


Nominal 
Diam. 
A 

B 

c 

D 

E 

X 

F 

G 

Class. 

4 

4 

11 

23 

11 

D 

6 

4 

12 

24 

12 

D 

6 

6 

12 

24 

12 

D 

8 

4 

13 

25 

13 

D 

8 

6 

13 

25 

13 

D 

8 

8 

13 

25 

13 

D 

10 

4 

14 

26 

14 

D 

10 

6 

14 

26 

14 

D 

10 

8 

14 

26 

14 

D 

10 

10 

14 

26 

14 

D 

12 

4 

15 

27 

15 

D 

12 

6 

15 

27 

15 

D 

12 

8 

15 

27 

15 

D 

12 

10 

15 

27 

15 

D 

12 
14 

12 
4 

15 
16 

27 
28 

15 
16 

1.25 

1.62 

2.50 

D 
A-B 

14 

4 

16 

28 

16 

C-D 

14 

6 

16 

28 

16 

A-B 

14 

6 

16 

28 

16 

C-D 

14 

8 

16 

28 

16 

A-B 

14 

8 

16 

28 

16 

C-D 

14 

10 

16 

28 

16 

A-B 

14 

10 

16 

28 

16 

C-D 

14 
14 

12 
12 

16 
16 

28 
28 

16 
16 

1.25 
1.25 

1.62 
1.62 

2.50 
2.50 

A-B 
C-D 

428 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE  NO.  6.— BRANCHES  (Continued). 
(Dimensions  in  Inches.) 


Nominal 
Diam. 
A 

B 

C 

D 

E 

X 

Y 

G 

Class. 

14 
14 
16 

14 
14 
4 

16 
16 
17 

28 
28 
29 

16 
16 

17 

1.25 
1.25 

1.62 
1.62 

2.50 
2.50 

A-B 
C-D 
A-B 

16 

4 

17 

29 

17 

C-D 

16 

6 

17 

29 

17 

A-B 

16 

6 

17 

29 

17 

C-D 

16 

6 

17 

29 

17 

A-B 

16 

6 

17 

29 

17 

C-D 

16 

8 

17 

29 

17 

A-B 

16 

8 

17 

29 

17 

C-D 

16 

10 

17 

29 

17 

A-B 

16 

10 

17 

29 

17 

C-D 

16 
16 
16 
16 
16 
16 
18 

12 
12 
14 
14 
16 
16 
4 

17 
17 
17 
17 
17 
17 
18 

29 
29 
29 
29 
29 
29 
30 

17 
17 
17 
17 
17 
17 
18 

1.25 
1.25 
1.25 
1.25 
1.25 
1.25 

1.62 
1.62 
1.62 
1.62 
1.62 
1.62 

2.50 
2.50 
2.50 
2.50 
2.50 
2.50 

A-B 
C-D 
A-B 
C-D 
A-B 
C-D 
A-B 

18 

4 

18 

30 

18 

C-D 

18 

6 

18 

30 

18 

A-B 

18 

6 

18 

30 

18 

C-D 

18 

8 

18 

30 

18 

A-B 

18 

8 

18 

30 

18 

C-D 

18 

10 

18 

30 

18 

A-B 

18 

10 

18 

30 

18 

C-D 

18 
18 
18 
18 
18 
18 
18 
18 
20 
20 

12 
12 
14 
14 
16 
16 
18 
18 
6 
6 

18 
18 
18 
18 
18 
18 
18 
18 
19 
19 

30 
30 
30 
30 
30 
30 
30 
30 
31 
31 

18 
18 
18 
18 
18 
18 
18 
18 
19 
19 

1.25 
1.25 
1.25 
1.25 
1.25 
1.25 
1.25 
1.25 
1.25 

1.62 
1.62 
1.62 
1.62 
1.62 
1.62 
1.62 
1.62 
1.62 

2.50 
2.50 
2.50 
2.50 
2.50 
2.50 
2.50 
2.50 
2.50 

A-B 
C-D 
A-B 
C-D 
A-B 
C-D 
A-B 
C-D 
A-B 
C-D 

20 

8 

19 

31 

19 

A-B 

20 

g 

19 

31 

19 

C-D 

20 

10 

19 

31 

19 

A-B 

20 

10 

19 

31 

19 

C-D 

20 
20 
20 
20 
20 
20 
20 
20 

12 
12 
14 
14 
16 
16 
18 
18 

19 
19 
19 
19 
19 
19 
19 
19 

31 
31 
31 
31 
31 
31 
31 
31 

19 
19 
19 
19 
19 
19 
19 
19 

.25 
.25 
.25 
.25 
.25 
.25 
25 
.25 

.62 
.62 
.62 
.62 
.62 
.62 
.62 
1.62 

2.50 
2.50 
2.50 
2.50 
2.50 
2.50 
2.50 
2.50 

A-B 
C-D 
A-B 
C-D 
A-B 
C-D 
A-B 
C-D 

PIPE  AND  MISCELLANEOUS  DATA. 


429 


TABLE   NO.  6.— BRANCHES  (Continued). 
(Dimensions  in  Inches.) 


Nominal 
Diam. 
A 

B 

C 

D 

E 

X 

Y 

G 

Class. 

20 

20 

19 

31 

19 

1.25 

1.62 

2.50 

A-B 

20 

20 

19 

31 

19 

1.25 

1.62 

2.50 

C-D 

24 

6 

21 

33 

21 

A-B 

24 

6 

21 

33 

21 

C-D 

24 

8 

21 

33 

21 

A-B 

24 

8 

21 

33 

21 

C-D 

24 

10 

21 

33 

21 

A-B 

24 

10 

21 

33 

21 

C-D 

24 

12 

21 

33 

21 

1.25 

1.62 

2.50 

A-B 

24 

12 

21 

33 

21 

1.25 

.62 

2.50 

C-D 

24 

14 

21 

33 

21 

1.25 

.62 

2.50 

A-B 

24 

14 

21 

33 

21 

.25 

.62 

2.50 

C-D 

24 

16 

21 

33 

21 

.25 

.62 

2.50 

A-B 

24 

16 

21 

33 

21 

.25 

.62 

2.50 

C-D 

24 

18 

21 

33 

21 

.25 

1.62 

2.50 

A-B 

24 

18 

21 

33 

21 

.25 

1.62 

2.50 

C-D 

24 

20 

21 

33 

21 

.25 

1.62 

2.50 

A-B 

24 

20 

21 

33 

21  . 

.25 

1.62 

2.50 

C-D 

24 

24 

21 

33 

21 

.25 

.62 

2.50 

A-B 

24 

24 

21 

33 

21 

.25 

.62 

2.50 

C-D 

30 

12 

15 

27 

24 

.25 

.62 

2.50 

A 

30 

12 

15 

27 

24 

.25 

.62 

2.50 

B 

30 

12 

15 

27 

24 

.25 

.62 

2.50 

C 

30 

12 

15 

27 

24 

.25 

.62 

2.50 

D 

30 

14 

16 

28 

24 

.25 

.62 

2.50 

A 

30 

14 

16 

28 

24 

.25 

.62 

2.50 

B 

30 

14 

16 

28 

24 

.25 

.62 

2.50 

C 

30 

14 

16 

28 

24 

.25 

1.62 

2.50 

D 

30 

16 

17 

29 

24 

1.25 

1.62 

2.50 

A 

30 

16 

17 

29 

24 

1.25 

1.62 

2.50 

B 

30 

16 

17 

29 

24 

1.25 

1.62 

2.50 

C 

30 

16 

17 

29 

24 

.25 

1.62 

2.50 

D 

30 

18 

18 

32 

24 

.25 

1.62 

2.50 

A 

30 

18 

18 

32 

24 

.25 

1.62 

2.50 

B 

30 

18 

18 

32 

24 

.25 

1.62 

2.50 

C 

30 

18 

18 

32 

24 

.25 

1.62 

2.50 

D 

30 

20 

19 

34 

24 

.25 

1.62 

2.50 

A 

30 

20 

19 

34 

24 

.25 

1.62 

2.50 

B 

30 

20 

19 

34 

24 

.25 

1.62 

2.50 

C 

30 

20 

19 

34 

24 

.25 

1.62 

2.50 

D 

30 

24 

21 

36 

24 

.25 

1.62 

2.50 

A 

30 

24 

21 

36 

24 

.25 

1.62 

2.50 

B 

30 

24 

21 

36 

24 

.25 

1.62 

2.50 

C 

30 

24 

21 

36 

24 

.25 

1.62 

2.50 

D 

30 

30 

24 

41 

24 

.50 

2.00 

3.00 

A 

30 

30 

24 

41 

24 

.50 

2.00 

3.00 

B 

30 

30 

24 

41 

24 

.50 

2.00 

3.00 

C 

30 

30 

24 

41 

24 

.50 

2.00 

3.00 

D 

430 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE   NO.  6.— BRANCHES  (Continued). 
(Dimensions  in  Inches.) 


Nominal 
Diam. 
A 

B 

C 

D 

E 

X 

Y 

G 

Class. 

36 

12 

15 

27 

27 

1.25 

1.62 

2.50 

A 

36 

12 

15 

27 

27 

1.25 

1.62 

2.50 

B 

36 

12 

15 

27 

27 

1.25 

1.62 

2.50 

C 

36 

12 

15 

27 

27 

.25 

1.62 

2.50 

D 

36 

.  14 

16 

28 

27 

.25 

1.62 

2.50 

A 

36 

14 

16 

28 

27 

.25 

1.62 

2.50 

B 

36 

14 

16 

28 

27 

.25 

1.62 

2.50 

C 

36 

14 

16 

28 

27 

.25 

1.62 

2.50 

D 

36 

16 

17 

29 

27 

.25 

1.62 

2.50 

A 

36 

16 

17 

29 

27 

.25 

.62 

2.50 

B 

36 

16 

17 

29 

27 

.25 

.62 

2.50 

C 

36 

16 

17 

29 

27 

.25 

.62 

2.50 

D 

36 

18 

18 

32 

27 

.25 

.62 

2.50 

A 

36 

18 

18 

32 

27 

.25 

.62 

2.50 

B 

36 

18 

18 

32 

27 

.25 

.62 

2.50 

C 

36 

18 

18 

32 

27 

.25 

.62 

2.50 

D 

36 

20 

19 

34 

27 

.25 

.62 

2.50 

A 

36 

20 

19 

34 

27 

1.25 

.62 

2.50 

B 

36 

20 

19 

34 

27 

1.25 

.62 

2.50 

C 

36 

20 

19 

34 

27 

1.25 

.62 

2.50 

D 

36 

24 

21 

36 

27 

1.25 

.62 

2.50 

A 

36 

24 

21 

36 

27 

1.25 

.62 

2.50 

B 

36 

24 

21 

36 

27 

1.25 

1.62 

2.50 

C 

36 

24 

21 

36 

27 

1.25 

1.62 

2.50 

D 

36 

30 

24 

41 

27 

1.50 

2.00 

3.00 

A 

36 

30 

24 

41 

27 

1.50 

2.00 

3.00 

B 

36 

30 

24 

41 

27 

1.50 

2.00 

3.00 

C 

36 

30 

24 

41 

27 

1.50 

2.00 

3.00 

D 

36 

36 

27 

44 

27 

1.50 

2.00 

3.00 

A 

36 

36 

27 

44 

27 

1.50 

2.00 

3.00 

B 

36 

36 

27 

44 

27 

1.50 

2.00 

3.00 

C 

36 

36 

27 

44 

27 

1.50 

2.00 

3.00 

D 

42 

12 

15 

27 

30 

1.25 

1.62 

2.50 

A 

42 

12 

15 

27 

30 

1.25 

1.62 

2.50 

B 

42 

12 

15 

27 

30 

1.25 

1.62 

2.50 

C 

42 

12 

15 

27 

30 

1.25 

1.62 

2.50 

D 

42 

14 

16 

28 

30 

1.25 

1.62 

2.50 

A 

42 

14 

16 

28 

30 

1.25 

.62 

2.50 

B 

42 

14 

16 

28 

30 

1.25 

.62 

2.50 

C 

42 

14 

16 

28 

30 

1.25 

.62 

2.50 

D 

42 

16 

17 

29 

30 

1.25 

.62 

2.50 

A 

42 

16 

17 

29 

30 

1.25 

.62 

2.50 

B 

42 

16 

17 

29 

30 

1.25 

.62 

2.50 

C 

42 

16 

17 

29 

30 

1.25 

.62 

2.50 

D 

42 

18 

18 

32 

30 

1.25 

.62 

2.50 

A 

42 

18 

18 

32 

30 

1.25 

.62 

2.50 

B 

42 

18 

18 

32 

30 

1.25 

.62 

2.50 

C   > 

42 

18 

18 

32 

30 

1.25 

.62 

2.50 

D 

PIPE  AND  MISCELLANEOUS  DATA. 


431 


TABLE   NO.  6—  BRANCHES  (Continued). 
(Dimensions  in  Inches.) 


Nominal 
Diam. 
A 

B 

C 

D 

E 

X 

Y 

G 

Class. 

42 

20 

19 

34 

30 

1.25 

1.62 

2.50 

A 

42 

20 

19 

34 

30 

1.25 

1.62 

2.50 

B 

42 

20 

19 

34 

30 

1.25 

1.62 

2.50 

C 

42 

20 

19 

34 

30 

1.25 

1.62 

2.50 

D 

42 

24 

21 

36 

30 

1.25 

1.62 

2.50 

A 

42 

24 

21 

36 

30 

1.25 

1.62 

2.50 

B 

42 

24 

21 

36 

30 

1.25 

1.62 

2.50 

C 

42 

24 

21 

36 

30 

1.25 

1.62 

2.50 

D 

42 

30 

24 

41 

30 

1.50 

2.00 

3.00 

A 

42 

30 

24 

41 

30 

1.50 

2.00 

3.00 

B 

42 

30 

24 

41 

30 

1.50 

2.00 

3.00 

C 

42 

30 

24 

41 

30 

1.50 

2.00 

3.00 

D 

42 

36 

27 

44 

30 

1.50 

2.00 

3.00 

A 

42 

36 

27 

44 

30 

1.50 

2.00 

3.00 

B 

42 

36 

27 

44 

30 

1.50 

2.00 

3.00 

C 

42 

36 

27 

44 

30 

1.50 

2.00 

3.00 

D 

42 

,  42 

30 

47  • 

30 

1.50 

2.00 

3.00 

A 

42 

,  42 

30 

47 

30 

1.50 

2.00 

3.00 

B 

42 

42 

30 

47 

30 

1.50 

2.00 

3.00 

C 

42 

42 

30 

47 

30 

1.50 

2.00 

3.00 

D 

48 

16 

17 

29 

33 

1.25 

1.62 

2.50 

A 

48 

16 

17 

29 

33 

1.25 

1.62 

2.50 

B 

48 

16 

17 

29 

33 

1.25 

1.62 

2.50 

C 

48 

16 

17 

29 

33 

1.25 

1.62 

2.50 

D 

48 

18 

18 

32 

33 

1.25 

1.62 

2.50 

A 

48 

18 

18 

32 

33 

1.25 

1.62 

2.50 

B 

48 

18 

18 

32 

33 

1.25 

1.62 

2.50 

C 

48 

18 

18 

32 

33 

.25 

1.62 

2.50 

D 

48 

20 

19 

34 

33 

.25 

1.62 

2.50 

A 

48 

20 

19 

34 

33 

.25 

1.62 

2.50 

B 

48 

20 

19 

34 

33 

.25 

1.62 

2.50 

C 

48 

20 

19 

34 

33 

.25 

1.62 

2.50 

D 

48 

24 

21 

36 

33 

1.25 

1.62 

2.50 

A 

48 

24 

21 

36 

33 

1.25 

1.62 

2.50 

B 

48 

24 

21 

36 

33 

1.25 

1.62 

2.50 

C 

48 

24 

21 

36 

33 

1.25 

1.62 

2.50 

D 

48 

30 

24 

41 

33 

1.50 

2.00 

3.00 

A 

48 

30 

24 

41 

33 

1.50 

2.00 

3.00 

B 

48 

30 

24 

41 

33 

1.50 

2.00 

3.00 

C 

48 

30 

24 

41 

33 

1.50 

2.00 

3.00 

D 

48 

36 

27 

44 

33 

1.50 

2.00 

3.00 

A 

48 

36 

27 

44 

33 

1.50 

2.00 

3.00 

B 

48 

36 

27 

44 

33 

1.50 

2.00 

3.00 

C 

48 

36 

27 

44 

33 

1.50 

2.00 

3.00 

D 

48 

42 

30 

47 

33 

1.50 

2.00 

3.00 

A 

48 

42 

30 

47 

33 

1.50 

2.00 

3.00 

B 

48 

42 

30 

47 

33 

1.50 

2.00 

3.00 

C 

48 

42 

30 

47 

33 

1.50 

2.00 

3.00 

D 

432 


AMERICAN  GAS-ENGINEERING   PRACTICE. 


TABLE   NO.  6— BRANCHES  (Continued). 
(Dimensions  in  Inches.) 


Nominal 
Diam. 
A 

B 

C 

D 

E 

X 

Y 

G 

Class. 

48 

48 

33 

50 

33 

1.50 

2.00 

3.00 

A 

48 

48 

33 

50 

33 

1.50 

2.00 

3.00 

B 

48 

48 

33 

50 

33 

1.50 

2.00 

3.00 

C 

48 

48 

33 

50 

33 

1.50 

2.00 

3.00 

D 

54 

16 

17 

29 

36 

1.25 

1.62 

2.50 

A 

54 

16 

17 

29 

36 

1.25 

1.62 

2.50 

B 

54 

16 

17 

29 

36 

1.25 

1.62 

2.50 

C 

54 

16 

17 

29 

36 

1.25 

1.62 

2.50 

D 

54 

18 

18 

32 

36 

1.25 

1.62 

2.50 

A 

54 

18 

18 

32 

36 

1.25 

1.62 

2.50 

B 

54 

18 

18 

32 

36 

1.25 

1.62 

2.50 

C 

54 

18 

18 

32 

36 

1.25 

1.62 

2.50 

D 

54 

20 

19 

34 

36 

1.25 

1.62 

2.50 

A 

54 

20 

19 

34 

36 

1.25 

1.62 

2.50 

B 

54 

20 

19 

34 

36 

1.25 

1.62 

2.50 

C 

54 

20 

19 

34 

36 

1.25 

1.62 

2.50 

D 

54 

24 

21 

36 

36 

1.25 

1.62 

2.50 

A 

54 

24 

21 

36 

36 

1.25 

1.62 

2.50 

B 

54 

24 

21 

36 

36 

1.25 

1.62 

2.50 

C 

54 

24 

21 

36 

36 

1.25 

1.62 

2.50 

D 

54 

30 

24 

41 

36 

1.50 

2.00 

3.00 

A 

54 

30 

24 

41 

36 

1.50 

2.00 

3.00 

B 

54 

30 

24 

41 

36 

1.50 

2.00 

3.00 

C 

54 

30 

24 

41 

36 

1.50 

2.00 

3.00 

D 

54 

36 

27 

44 

36 

1.50 

2.00 

3.00 

A 

54 

36 

27 

44 

36 

1.50 

2.00 

3.00 

B 

54 

36 

27 

44 

36 

1.50 

2.00 

3.00 

C 

54 

36 

27 

44 

36 

1.50 

2.00 

3.00 

D 

54 

42 

30 

47 

36 

1.50 

2.00 

3.00 

A 

54 

42 

30 

47 

36 

1.50 

2.00 

3.00 

B 

54 

42 

30 

47 

36 

1.50 

2.00 

3.00 

C 

54 

42 

30 

47 

36 

1.50 

2.00 

3.00 

D 

54 

48 

33 

50 

36 

l.£0 

2.00 

3.00 

A 

54 

48 

33 

50 

36 

1.50 

2.00 

3.00 

B 

54 

48 

33 

50 

36 

1.50 

2.00 

3.00 

C 

54 

48 

33 

50 

36 

1.50 

2.00 

3.00 

D 

54 

54 

36 

53 

36 

1.50 

2.00 

3.00 

A 

54 

54 

36 

53 

36 

1.50 

2.00 

3.00 

B 

54 

54 

36 

53 

36 

1.50 

2.00 

3.00 

C 

54 

54 

36 

53 

36 

1.50 

2.00 

3.00 

D 

60 

16 

17 

29 

39 

1.25 

1.62 

2.50 

A 

60 

16 

17 

29 

39 

1.25 

1.62 

2.50 

B 

60 

16 

17 

29 

39 

1.25 

1.62 

2.50 

C 

60 

16 

17 

29 

39 

1.25 

1.62 

2.50 

D 

60 

18 

18 

32 

39 

1.25 

1.62 

2.50 

A 

60 

18 

18 

32 

39 

1.25 

1.62 

2.50 

B 

60 

18 

18 

32 

39 

1.25 

1.62 

2.50 

C 

60 

18 

18 

32 

39 

1.25 

1.62 

2.50 

D 

PIPE  AND  MISCELLANEOUS  DATA. 


433 


TABLE   NO.  6— BRANCHES  (Continued). 
(Dimensions  in  Inches.) 


Nominal 
Diam. 
A 

B 

C 

D 

E 

X 

Y 

G 

Class. 

60 

20 

19 

34 

39 

1.25 

1.62 

2.50 

A 

60 

20 

19 

34 

39 

1.25 

1.62 

2.50 

B 

60 

20 

19 

34 

39 

1.25 

1.62 

2.50 

C 

60 

20 

19 

34 

39 

1.25 

1.62 

2.50 

D 

60 

24 

21 

36 

39 

1.25 

1.62 

2.50 

A 

60 

24 

21 

36 

39 

1.25 

1.62 

2.50 

B 

60 

24 

21 

36 

39 

1.25 

1.62 

2.50 

C 

60 

24 

21 

36 

39 

1.25 

1.62 

2.50 

D 

60 

30 

24 

41 

39 

1.50 

2.00 

3.00 

A 

60 

30 

24 

41 

39 

1.50 

2.00 

3.00 

B 

60 

30 

24 

41 

39 

1.50 

2.00 

3.00 

C 

60 

30 

24 

41 

39 

1.50 

2.00 

3.00 

D 

60 

36 

27 

44 

39 

.50 

2.00 

3.00 

A 

60 

36 

27 

44 

39 

.50 

2.00 

3.00 

B 

60 

36 

27 

44 

39 

.50 

2.00 

3.00 

C 

60 

36 

27 

44 

39 

.50 

2.00 

3.00 

D 

60 

42 

30 

47 

39 

.50 

2.00 

3.00 

A 

60 

42 

30 

47 

39 

.50 

2.00 

3.00 

B 

60 

42 

30 

47 

39 

.50 

2.00 

3.00 

C 

60 

42 

30 

47 

39 

.50 

2.00 

3.00 

D 

60 

48 

33 

50 

39 

.50 

2.00 

3.00 

A 

60 

48 

33 

50 

39 

.50 

2.00 

3.00 

B 

60 

48 

33 

50 

39 

1.50 

2.00 

3.00 

C 

60 

48 

33 

50 

39 

1.50 

2.00 

3.00 

D 

60 

54 

36 

53 

39 

1.50 

2.00 

3.00 

A 

60 

54 

36 

53 

39 

1.50 

2.00 

3.00 

B 

60 

54 

36 

53 

39 

1.50 

2.00 

3.00 

C 

60 

54 

36 

53 

39 

1.50 

2.00 

3.00 

D 

60 

60 

39 

56 

39 

1.50 

2.00 

3.00 

A 

60 

60 

39 

56 

39 

1.50 

2.00 

3.00 

B 

60 

60 

39 

56 

39 

1.50 

2.00 

3.00 

C 

60 

60 

39 

56 

39 

1.50 

2.00 

3.00 

D 

434 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TYPE  1.— 12"  to  48". 


G=2.50"  for  12"  to  24"  bells. 
X=  1.25"  for  12"  to  24"  bells. 
F=  1.62"  for  12"  to  24"  bells. 
Z=  1.00"  for  12"  to  14"  bells. 


G=3.00"  for  30"  to  60"  bells. 
X  =  1.50"  for  30"  to  60"  bells. 
Y  =  2.00"  for  30"  to  60"  bells. 
Z=  1.25"  for  16"  to  30"  bells. 
Z=1.50"  for  36"  to  60"  bells. 


TYPE  2.— 4"  to  16". 

TABLE   NO.  7.— Y  BRANCHES. 
(Dimensions  in  Inches.) 


Nom.Diam. 

S 

P 

V 

W 

N 

R 

T! 

T2 

T3 

Type 

Class. 

E 

F 

4 

4 

11.5 

10.5 

7  18 

6.64 

3.18 

6 

0.52 

0.65 

2 

D 

6 

6 

is!o 

13.0 

9.27 

7.46 

4.27 

6 

0.55 

0.68 

2 

D 

8 

8 

14.0 

16.0 

11.85 

8.30 

4.85 

6 

0.60 

0.72 

2 

D 

10 

10 

15.5 

18.5 

13.94 

9.12 

5.94 

6 

0.68 

0.85 

2 

D 

12 

12 

15.5 

21.5 

16.54 

9.92 

5.54 

6 

0.75 

0.95 



2 

D 

12 

12 

16.0 

21.5 

8.00 

9.79 

1.19 

30 

0.75 

1.10 

6.75 

1 

D 

14 

14 

16.0 

24.0 

18.62 

10.76 

5.62 

6 

0.66 

0.80 

2 

A-B 

14 

14 

16.0 

24.0 

18.62 

10.76 

5.62 

6 

0.82 

1.00 

2 

C-D 

14 

14 

16.0 

24.0 

9.00 

11.30 

1.00 

30 

0.66 

0.90 

'6'.66 

1 

A-B 

14 

14 

16.0 

24.0 

9  00 

11.30 

1.29 

30 

0.82 

1.19 

0.82 

1 

C-D 

PIPE  AND  MISCELLANEOUS  DATA. 


435 


TABLE   NO.  7.— Y  BRANCHES  (Continued). 
(Dimensions  in  Inches.) 


Nom.Diam. 

.  

S 

P 

V 

W 

N 

R 

Ti 

T2 

Ta 

Class. 

E 

F 

16 

16 

17.5 

27.5 

21.70 

11.60 

6.70 

6 

0.70 

0.85 

A-B 

16 

16 

17.5 

27.5 

21.70 

11.60 

6.70 

6 

0.89 

1.10 

C-D 

16 

16 

17.0 

27.5 

10.50 

13.00 

1.10 

30 

0.70 

1.00 

o!70 

A-B 

16 

16 

17.0 

27.5 

10.50 

13.00 

1.50 

30 

0.89 

1.30 

0.89 

C-D 

18 

18 

18.0 

30.0 

12.0 

14.7 

1.17 

30 

0.75 

1.08 

0.75 

A-B 

18 

18 

18.0 

30.0 

12.0 

14.7 

1.36 

30 

0.96 

1.40 

0.96 

C-D 

20 

20 

18.0 

34.0 

13.5 

16.4 

1.25 

30 

0.80 

1.15 

0.80 

A-B 

20 

20 

18.0 

34.0 

13.5 

16.4 

1.62 

30 

1.03 

1.50 

1.03 

C-D 

24 

18 

9.0 

30.0 

12.0 

14.7 

1.17 

30 

0.89 

1.08 

0.75 

A-B 

24 

18 

9.0 

30.0 

12.0 

14.7 

1.36 

30 

1.16 

1.40 

0.96 

C-D 

24 

20 

12.0 

34.0 

13.5 

16.4 

1.25 

30 

0.89 

.15 

0.80 

A-B 

24 

20 

12.0 

34.0 

13.5 

16.4 

1.62 

30 

1.16 

1.50 

1.03 

C-D 

24 

24 

18.0 

38.0 

15.25 

19.3 

1.41 

30 

0.89 

.30 

0.89 

A-B 

24 

24 

18.0 

38.0 

15.25 

19.3 

1.84 

30 

1.16 

.70 

1.16 

C-D 

30 

24 

12.0 

38.0 

15.25 

19.3 

1.35 

30 

0.88 

.25 

0.89 

A 

30 

24 

12.0 

38.0 

15.25 

19.3 

1.35 

30 

1.03 

.25 

0.89 

B 

30 

24 

12.0 

38.0 

15.25 

19.3 

1.79 

30 

1.20 

.65 

1.16 

C 

30 

24 

12.0 

38.0 

15.25 

19.3 

1.79 

30 

1.37 

.65 

1.16 

D 

30 

30 

18 

48 

18 

23.7 

1.35 

30 

0.88 

.25 

0.88 

A 

30 

30 

18 

48 

18 

23.7 

1.62 

30 

1.03 

.50 

1.03 

B 

30 

30 

18 

48 

18 

23.7 

1.89 

30 

1.20 

.75 

1.20 

C 

30 

30 

18 

48 

18 

23.7 

2.16 

30 

1.37 

2.00 

1.37 

D 

36 

30 

10 

48 

18 

23.7 

1.35 

30 

0.99 

1.25 

0.88 

A 

36 

30 

10 

48 

18 

23.7 

1.62 

30 

1.15 

1.50 

1.03 

B 

36 

30 

10 

48 

18 

23.7 

1.89 

30 

.36 

1.75 

1.20 

C 

36 

30 

10 

48 

18 

23.7 

2.16 

30 

.58 

2.00 

1.37 

D 

36 

36 

18 

54 

21 

28.2 

1.62 

24 

.99 

1.50 

0.99 

A 

36 

36 

18 

54 

21 

28.2 

1.79 

24 

.15 

1.65 

1.15 

B 

36 

36 

18 

54 

21 

28.2 

2.16 

24 

.36 

2.00 

1.36 

C 

36 

36 

18 

54 

21 

28.2 

2.54 

24 

.58 

2.35 

1.58 

D 

42 

30 

6 

48 

18 

23.7 

1.35 

30 

.10 

1.25 

0.88 

A 

42 

30 

6 

48 

18 

23.7 

1.62 

30 

.28 

1.50 

1.03 

B 

42 

30 

6 

48 

18 

23.7 

1.89 

30 

.54 

1.75 

1.20 

C 

42 

30 

6 

48 

18 

23.7 

2.16 

30 

.78 

2.00 

1.37 

D 

42 

36 

10 

54 

21 

28.2 

1.62 

24 

.10 

1.50 

0.99 

A 

42 

36 

10 

54 

21 

28.2 

1.79 

24 

.28 

1.65 

1.15 

B 

42 

36 

10 

54 

21 

28.2 

2.16 

24 

.54 

2.00 

.36 

C 

42 

36 

10 

54 

21 

28.2 

2.54 

24 

.78 

2.35 

.58 

D 

42 

42 

18 

60 

25 

33.1 

1.79 

24 

.10 

1.65 

.10 

A 

42 

42 

18 

60 

25 

33.1 

1.95 

24 

.28 

1.80 

.28 

B 

42 

42 

18 

60 

25 

33.1 

2.44 

24 

.54 

2.25 

.54 

C 

42 

42 

18 

60 

25 

33.1 

2.87 

24 

.78 

2.65 

.78 

D 

48 

36 

2 

54 

21 

28.2 

1.62 

24 

.26 

1.50 

.99 

A 

48 

36 

2 

54 

21 

28.2 

1.79 

24 

.42 

1.65 

.15 

B 

48 

36 

2 

54 

21 

28.2 

2.16 

24 

.71 

2.00 

.36 

C 

48 

36 

2 

54 

21 

28.2 

2.54 

24 

.96 

2.35 

.58 

D 

436 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE   NO.  7  (Continued). 
(Dimensions  in  Inches.) 


Nom.Diam 

s 

P 

F 

w 

N 

R 

T! 

T2 

T3 

Class. 

E 

F 

48 

42 

10 

60 

25 

33.1 

1.79 

24 

1.26 

1.65 

1.10 

A 

48 

42 

10 

60 

25 

33.1 

1.95 

24 

1.42 

1.80 

1.28 

B 

48 

42 

10 

60 

25 

33.1 

2.44 

24 

1.71 

2.25 

1.54 

C 

48 

42 

10 

60 

25 

33.1 

2.87 

24 

1.96 

2.65 

1.78 

D 

48 

48 

18 

68.5 

28 

37.6 

1.95 

24 

1.26 

1.80 

1.26 

A 

48 

48 

18 

68.5 

28 

37.6 

2.27 

24 

1.42 

2.10 

1.42 

B 

48 

48 

18 

68.5 

28 

37.6 

2.76 

24 

1.71 

2.55 

1.71 

C 

48 

48 

18 

68.5 

28 

37.6 

3.13 

24 

1.96 

2.90 

1.96 

D 

54 

36 

2 

54 

21 

28.2 

1.62 

24 

1.35 

1.50 

0.99 

A 

54 

36 

2 

54 

21 

28.2 

1.79 

24 

1.55 

1.65 

.15 

B 

54 

36 

2 

54 

21 

28.2 

2.16 

24 

1.90 

2.00 

.36 

C 

54 

36 

2 

54 

21 

28.2 

2.54 

24 

2.23 

2.35 

.58 

D 

54 

42 

6 

60 

25 

33.1 

1.75 

24 

1.35 

1.65 

.10 

A 

54 

42 

6 

60 

25 

33.1 

1.95 

24 

1.55 

1.80 

.28 

.  B 

54 

42 

6 

60 

25 

33.1 

2.44 

24 

1.90 

2.25 

.54 

C 

54 

42 

6 

60 

25 

33.1 

2.87 

24 

2.23 

2.65 

.78 

D 

54 

48 

10 

68.5 

28 

37.6 

1.95 

24 

1.35 

1.80 

.26 

A 

54 

48 

10 

68.5 

28 

37.6 

2.27 

24 

1.55 

2.10 

.42 

B 

54 

48 

10 

68.5 

28 

37.6 

2.76 

24 

1.90 

2.55 

.71 

C 

54 

48 

10 

68.5 

28 

37.6 

3.13 

24 

2.23 

2.90 

.96 

D 

54 

54 

18 

78 

31 

42 

2.16 

24 

1.35 

2.00 

.35 

A 

54 

54 

18 

78 

31 

42 

2.44 

24 

1.55 

2.25 

1.55 

B 

54 

54 

18 

78 

31 

42 

3.08 

24 

1.90 

2.85 

1.90 

C 

54 

54 

18 

78 

31 

42 

3.50 

24 

2.23 

3.25 

2.23 

D 

60 

36 

2 

54 

21 

28.2 

1.62 

24 

1.39 

1.50 

0.99 

A 

60 

36 

2 

54 

21 

28.2 

1.79 

24 

1.67 

1.65 

1.15 

B 

60 

36 

2 

54 

21 

28.2 

2.16 

24 

2.00 

2.00 

1.36 

C 

60 

36 

2 

54 

21 

28.2 

2.54 

24 

2.38 

2.35 

1.58 

D 

60 

42 

6 

60 

25 

33.1 

1.75 

24 

1.39 

1.65 

1.10 

A 

60 

42 

6 

60 

25 

33.1 

1.95 

24 

1.67 

1.80 

.28 

B 

60 

42 

6 

60 

25 

33.1 

2.44 

24 

2.00 

2.25 

.54 

C 

60 

42 

6 

60 

25 

33.1 

2.87 

24 

2.38 

2.65 

.78 

D 

60 

48 

8 

68.5 

28 

37.6 

1.95 

24 

1.39 

1.80 

.26 

A 

60 

48 

8 

68.5 

28 

37.6 

2.27 

24 

1.67 

2.10 

.42 

B 

60 

48 

8 

68.5 

28 

37.6 

2.76 

24 

2.00 

2.55 

1.71 

C 

60 

48 

8 

68.5 

28 

37.6 

3.13 

24 

2.38 

2.90 

1.96 

D 

60 

54 

12 

78 

31 

42 

2.16 

24 

1.39 

2.00 

1.35 

A 

60 

54 

12 

78 

31 

42 

2.44 

24 

1.67 

2.25 

1.55 

B 

60 

54 

12 

78 

31 

42 

3.08 

24 

2.00 

2.85 

1.90 

C 

60 

54 

12 

78 

31 

42 

3.50 

24 

2.38 

3.25 

2.23 

D 

60 

60 

18 

90 

35 

46.7 

2.22 

24 

1.39 

2.05 

1.39 

A 

60 

60 

18 

90 

35 

46.7 

2.70 

24 

1.67 

2.50 

1.67 

B 

60 

60 

18 

90 

35 

46.7 

3.25 

24 

2.00 

3.00 

2.00 

C 

60 

60 

18 

90 

35 

46.7 

3.78 

24 

2.38 

3.50 

2.38 

D 

PIPE  AND  MISCELLANEOUS  DATA. 


437 


TABLE  NO.  8.— BLOW-OFF  BRANCHES. 
(Dimensions  in  Inches.) 


Norn. 

Diam. 

T 

T 

T 

•y 

E 

F 

•*  1 

*2 

8 

4 

12 

7 

0.60 

0  52 

D 

10 

4 

12 

8 

0.68 

0.52 

D 

10 

6 

12 

8 

0.68 

0.55 

D 

12 

4 

12 

10 

0.75 

0.52 

D 

12 

6 

12 

10 

0  75 

0  55 

D 

14 

4 

12 

11 

0  66 

0  52 

A-B 

14 

4 

12 

11 

0  82 

0  52 

C-D 

14 

6 

12 

11 

0  66 

0  55 

A-B 

14 

6 

12 

11 

0  82 

0  55 

C-D 

16 

4 

12 

12 

0  70 

0  52 

A-B 

16 

4 

12 

12 

0  89 

0  52 

C-D 

16 

6 

12 

12 

0  70 

0.55 

A-B 

16 

6 

12 

12 

0.89 

0.55 

C-D 

18 

4 

12 

13 

0  75 

0  52 

A  B 

18 

4 

12 

13 

0  96 

0  52 

C-D 

18 

6 

12 

13 

0  75 

0  55 

A-B 

18 

6 

12 

13 

0  96 

0  55 

C-D 

20 

4 

12 

14 

0  80 

0  52 

A-B 

20 

4 

12 

14 

1  03 

0  52 

C-D 

20 

6 

12 

14 

0.80 

0  55 

A-B 

20 

6 

12 

14 

1.03 

0.55 

C-D 

24 

6 

12 

16 

0.89 

0.55 

A-B 

24 

6 

12 

16 

1  16 

0  55 

C-D 

24 

8 

12 

16 

0  89 

0  60 

A-B 

24 

8 

12 

16 

1  16 

0  60 

C-D 

30 

8 

13 

20 

0.88 

0.60 

A 

30 

8 

13 

20 

1.03 

0.60 

B 

30 

8 

13 

20 

1  20 

0  60 

c 

30 

8 

13 

20 

1  37 

0  60 

D 

438 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE    NO.  8  (Continued}. 
(Dimensions  in  Inches.) 


Nom. 

Diam. 

rrj 

/T? 

-\r 

E 

F 

L 

TI 

TZ 

A 

Class. 

30 

12 

13 

20 

0.88 

0.75 

1.25 

1.62 

2.50 

A 

30 

12 

13 

20 

1.03 

0.75 

1.25 

1.62 

2.50 

B 

30 

12 

13 

20 

.20 

0.75 

1.25 

1.62 

2.50 

C 

30 

12 

13 

20 

.37 

0.75 

1.25 

1.62 

2.50 

I) 

36 

8 

13 

23 

.99 

0.60 

A 

36 

8 

13 

23 

15 

0.60 

B 

Otl 

36 

8 

13 

23 

.36 

0.60 

C 

36 

8 

13 

23 

58 

0  60 

D 

36 

12 

13 

23 

.99 

0.75 

.25 

1.62 

2.50 

A 

36 

12 

13 

23 

.15 

0.75 

.25 

.62 

2.50 

B 

36 

12 

13 

23 

.36 

0.75 

.25 

.62 

2.50 

C 

36 

12 

13 

23 

.58 

0.75 

.25 

.62 

2.50 

D 

42 

12 

15 

26 

.10 

0.75 

.25 

.62 

2.50 

A 

42 

12 

15 

26 

.28 

0.75 

.25 

.62 

2.50 

B 

42 

12 

15 

26 

.54 

0.75 

.25 

.62 

2.50 

C 

42 

12 

15 

26 

.78 

0.75 

.25 

.62 

2.50 

D 

42 

16 

15 

26 

.10 

0.70 

.25 

.62 

2.50 

A 

42 

16 

15 

26 

.28 

0.70 

.25 

.62 

2.50 

B 

42 

16 

15 

26 

.54 

0.89 

.25 

.62 

2.50 

C 

42 

16 

15 

26 

.78 

0.89 

.25 

.62 

2.50 

D 

48 

12 

17 

30 

.26 

0.75 

.25 

.62 

2.50 

A 

48 

12 

17 

30 

.42 

0.75 

.25 

.62 

2.50 

B 

48 

12 

17 

30 

.71 

0.75 

.25 

.62 

2.50 

C 

48 

12 

17 

30 

.96 

0.75 

.25 

.62 

2.50 

D 

48 

16 

17 

30 

.26 

0.70 

.25 

.62 

2.50 

A 

48 

16 

17 

30 

1.42 

0.70 

.25 

.62 

2.50 

B 

48 

16 

17 

30 

1.71 

0.89 

.25 

.62 

2.50 

C 

48 

16 

17 

30 

1.96 

0.89 

.25 

.62 

2.50 

D 

54 

12 

19 

33 

1.35 

0.75 

.25 

.62 

2.50 

A 

54 

12 

19 

33 

1.55 

0.75 

1.25 

.62 

2.50 

B 

54 

12 

19 

33 

1.90 

0.75 

1.25 

.62 

2.50 

C 

54 

12 

19 

33 

2.23 

0.75 

1.25 

.62 

2.50 

D 

54 

16 

19 

33 

1.35 

0.70 

1.25 

.62 

2.50 

A 

54 

16 

19 

33 

1.55 

0.70 

1.25 

.62 

2.50 

B 

54 

16 

19 

33 

1  .90 

0.89 

1.25 

.62 

2.50 

C 

54 

16 

19 

33 

2  23 

0.89 

1.25 

.62 

2.50 

D 

60 

12 

21 

36 

1.39 

0.75 

1.25 

.62 

2.50 

A 

60 

12 

21 

36 

1.67 

0.75 

1.25 

.62 

2.50 

B 

60 

12 

21 

36 

2.00 

0.75 

1  .25 

1.62 

2.50 

C 

60 

12 

21 

36 

2.38 

0.75 

.25 

1.62 

2.50 

D 

60 

16 

21 

36 

1.39 

0.70 

.25 

1.62 

2.50 

A 

60 

16 

21 

36 

1.67 

0.70 

.25 

1.62 

2.50 

B 

60 

16 

21 

36 

2.00 

0.89 

.25 

1.62 

2.50 

C 

60 

16 

21 

36 

2.38 

0.89 

.25 

1.62 

2.50 

D 

PIPE  AND  MISCELLANEOUS  DATA. 
?X    2.0-  *k   BOUTS 


439 


TABLE   NO.  9.— BLOW-OFF   BRANCHES   WITH   MANHOLES. 
(Dimensions  in  Inches.) 


Nominal 

Diameter. 

T 

P 

N 

T 

T 

Plaaa 

E 

F 

JL/ 

i  \ 

•*•  2 

i^iass. 

30 

8 

17 

20 

21 

0.88 

0.60 

A 

30 

8 

17 

20 

21 

1.03 

0.60 

B 

30 

8 

17 

20 

21 

1.20 

0.60 

C 

30 

8 

17 

20 

21 

1.37 

0.60 

D 

30 

12 

17 

20 

21 

0.88 

0.75 

A 

30 

12 

17 

20 

21 

1.03 

0.75 

B 

30 

12 

17 

20 

21 

1.20 

0.75 

C 

30 

12 

17 

20 

21 

1.37 

0.75 

D 

36 

8 

17 

23 

24 

0.99 

0.60 

A 

36 

8 

17 

23 

24 

.15 

0.60 

B 

36 

8 

17 

23 

24 

.36 

0.60 

C 

36 

8 

17 

23 

24 

.58 

0.60 

D 

36 

12 

17 

23 

24 

0.99 

0.75 

A 

36 

12 

17 

23 

24 

.15 

0.75 

B 

36 

12 

17 

23 

24 

.36 

0.75 

C 

36 

12 

17 

23 

24 

1.58 

0.75 

D 

42 

12 

17 

26 

27 

1.10 

0.75 

A 

42 

12 

17 

26 

27 

1.28 

0.75 

B 

42 

12 

17 

26 

27 

1.54 

0.75 

C 

42 

12 

17 

26 

27 

1.78 

0.75 

D 

42 

16 

17 

26 

27 

1.10 

0.70 

A 

42 

16 

17 

26 

27 

1.28 

0.70 

B 

42 

16 

17 

26 

27 

1.54 

0.89 

C 

42 

16 

17 

26 

27 

1.78 

0.89 

D 

48 

12 

17 

30 

30 

1.26 

0.75 

A 

48 

12 

17 

30 

30 

1.42 

0.75 

B 

48 

12 

17 

30 

30 

1.71 

0.75 

C 

48 

12 

17 

30 

30 

1.96 

0.75 

D 

440 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE    NO.  9  (Continued). 
(Dimensions  in  Inches.) 


Nominal 

Diameter. 

jj 

p 

N 

T\ 

To 

Class. 

E 

F 

•*  2 

48 

16 

17 

30 

30 

.26 

0.70 

A 

48 

16 

17 

30 

30 

.42 

0.70 

B 

48 

16 

17 

30 

30 

.71 

0.89 

C 

48 

16 

17 

30 

30 

.96 

0.89 

D 

54 

12 

19 

33 

33 

.35 

0.75 

A 

54 

12 

19 

33 

33 

.55 

0.75 

B 

54 

12 

19 

33 

33 

1.90 

0.75 

C 

54 

12 

19 

33 

33 

2.23 

0.75 

D 

54 

16 

19 

33 

33 

1.35 

0.70 

A 

54 

16 

19 

33 

33 

1.55 

0.70 

B 

54 

16 

19 

33 

33 

1.90 

0.89 

C 

54 

16 

19 

33 

33 

2.23 

0.89 

D 

60 

12 

21 

36 

36 

1.39 

0.75 

A 

60 

12 

21 

36 

36 

1.67 

0.75 

B 

60 

12 

21 

36 

36 

2.00 

0.75 

C 

60 

12 

21 

36 

36 

2.38 

0.75 

D 

60 

16 

21 

36 

36 

1.39 

0.70 

A 

60 

16 

21 

36 

36 

1.67 

0.70 

B 

60 

16 

21 

36 

36 

2.00 

0.89 

C 

60 

16 

21 

36 

36 

2.38 

0.89 

D 

.-••—  ^-H.— 

- 

i 

-s-hK-r-M|-4— 

N 

TABLE    NO.  10.— REDUCERS. 

TYPE  1. 
(Dimensions  in  Inches.) 


Nom.  Diam. 

s 

K 

M 

N 

L 

R 

^ 

T2 

Class. 

E 

F 

6 

4 

10 

3.3 

14.7 

2 

30 

3 

0.55 

0.52 

D 

8 

4 

10 

5.3 

12.7 

2 

30 

4 

0.60 

0.52 

D 

8 

6 

10 

3.9 

14.1 

2 

30 

4 

0.60 

0.55 

D 

10 

4 

10 

7.1 

10.9 

2 

30 

5 

0.68 

0.52 

D 

10 

6 

10 

6.0 

12.0 

2 

30 

5 

0.68 

0.55 

D 

10 

8 

10 

4.4 

13.6 

2 

30 

5 

0.68 

0.60 

D 

12 

6 

10 

7.9 

10.1 

2 

30 

6 

0.75 

0.55 

D 

12 

8 

10 

6.6 

11.4 

2 

30 

6 

0.75 

0.60 

D 

12 

10 

10 

4.8 

13.2 

2 

30 

6 

0.75 

0.68 

D 

PIPE  AND  MISCELLANEOUS   DATA. 


441 


TABLE   NO.  11.— REDUCERS. 

TYPE  2. 
(Dimensions  in  Inches.) 


Nominal  Diameter. 

V 

S 

TI 

T2 

Class. 

E 

F 

14 

6 

20 

8 

0.66 

0.55 

A-B 

14 

6 

20 

8 

0.82 

0.55 

C-D 

14 

8 

20 

8 

0.66 

0.60 

A-B 

14 

8 

20 

8 

0.82 

0.60 

C-D 

14 

10 

20 

8  . 

0.66 

0.66 

A-B 

14 

10 

20 

8 

0.88 

0.68 

C-D 

14 

12 

20 

8 

0.66 

0.66 

A-B 

14 

12 

20 

8 

0.82 

0.75 

C-D 

16 

6 

20 

8 

0.70 

0.55 

A-B 

16 

6 

20 

8 

0.89 

0.55 

C-D 

16 

8 

20 

8 

0.70 

0.60 

A-B 

16 

8 

20 

8 

0.89 

0.60 

C-D 

16 

10 

20 

8 

0.70 

0.68 

A-B 

16 

10 

20 

8 

0.89 

0.68 

C-D 

16 

12 

20 

8 

0.70 

0.70 

A-B 

16 

12 

20 

8 

0.89 

0.75 

C-D 

16 

14 

20 

8 

0.70 

0.66 

A-B 

16 

14 

20 

8 

0.89 

0.82 

C-D 

18 

8 

20 

8 

0.75 

0.60 

A-B 

18 

8 

20 

8 

0.96 

0.60 

C-D 

18 

10 

20 

8 

0.75 

0.68 

A-B 

18 

10 

20 

8 

0.96 

0.68 

C-D 

18 

12 

20 

8 

0.75 

0.75 

A-B 

18 

12 

20 

8 

0.96 

0.75 

C-D 

18 

14 

20 

8 

0.75 

0.66 

A-B 

18 

14 

20 

8 

0.96 

0.82 

C-D 

18 

16 

20 

8 

0.75 

0.70 

A-B 

18 

16 

20 

8 

0.96 

0.89 

C-D 

20 

10 

26 

8 

0.80 

0.68 

A-B 

20 

10 

26 

8 

1.03 

0.68 

C-D 

442 


AMERICAN    GAS-ENGINEERING  PRACTICE. 


TABLE    NO.  11    (Continued). 
(Dimensions  in  Inches.) 


Nominal  Diameter. 

V 

s 

T! 

T2 

Class. 

E 

F 

20 

12 

20 

8 

0.80 

0.75 

A-B 

20 

12 

20 

8 

1.03 

0.75 

C-D 

20 

14 

26 

8 

0.80 

0.66 

A-B 

20 

14 

26 

8 

1.03 

0.82 

C-D 

20 

16 

26 

8 

0.80 

0.70 

A-B 

20 

16 

26 

8 

1.03 

0.89 

C-D 

20 

18 

26 

8 

0.80 

0.75 

A-B 

20 

18 

26 

8 

1.03 

0.96 

C-D 

24 

14 

26 

8 

0.89 

0.66 

A-B 

24 

14 

26 

8 

1.16 

0.82 

C-D 

24 

16 

26 

8 

0.89 

0.70 

A-B 

24 

16 

26 

8 

1.16 

0.89 

C-D 

24 

18 

26 

8 

0.89 

0.75 

A-B 

24 

18 

26 

8 

1.16 

0.96 

C-D 

24 

20 

26 

8 

0.89 

0.80 

A-B 

24 

20 

26 

8 

1.16 

1.03 

C-D 

30 

18 

26 

8 

0.88 

0.75 

A 

30 

18 

26 

8 

1.03 

0.75 

B 

30 

18 

26 

8 

1.20 

0.96 

C 

30 

18 

26 

8 

1.37 

0.96 

D 

30 

20 

26 

8 

0.88 

0.80 

A 

30 

20 

26 

8 

1.03 

0.80 

B 

30 

20 

26 

8 

1.20 

1.03 

C 

30 

20 

26 

8 

1.37 

1.03 

D 

30 

24 

26 

8 

0.88 

0.88 

A 

30 

24 

26 

8 

1.03 

0.89 

B 

30 

24 

26 

8 

1.20 

1.16 

C 

30 

24 

26 

8 

1.37 

1.16 

D 

36 

20 

32 

8 

0.99 

0.80 

A 

36 

20 

32 

8 

1.15 

0.80 

B 

36 

20 

32 

8 

1.36 

1.03 

C 

36 

20 

32 

8 

1.85 

1.03 

D 

36 

24 

32 

8 

0.99 

0.89 

A 

36 

24 

32 

8 

1.15 

0.89 

B 

36 

24 

32 

8 

1.36 

1.16 

C 

36 

24 

32 

8 

1.58 

1.16 

D 

36 

30 

32 

8 

0.99 

0.88 

A 

36 

30 

32 

8 

1.15 

1.03 

B 

36 

30 

32 

8 

1.36 

1.20 

C 

36 

30 

32 

8 

1.58 

1.37 

D 

42 

20 

32 

8 

1..10 

0.80 

A 

42 

20 

32 

8 

1.28 

0.80 

B 

42 

20 

32 

8 

1.54 

1.03 

C 

42 

20 

32 

8 

1.78 

1.03 

D 

42 

24 

32 

8 

1.10 

0.89 

A 

42 

24 

32 

8 

1.28 

0.89 

B 

42 

24 

32 

8 

1.54 

1.16 

C 

42 

24 

32 

8 

1.78 

1.16 

D 

PIPE  AND  MISCELLANEOUS  DATA. 


443 


TABLE   NO.  11    (Continued). 
(Dimensions  in  Inches.) 


Nominal 

Diameter. 

E 

F 

V 

S 

Ti 

T2 

Class. 

42 

30 

32 

8 

.10 

0.88 

A 

42 

30 

32 

8 

.28 

.03 

B 

42 

30 

32 

8 

.54 

.20 

C 

42 

30 

32 

8 

.78 

.37 

D 

42 

30 

66 

8 

.10 

0.88 

A 

42 

30 

66 

8 

.28 

.03 

B 

42 

30 

66 

8 

.54 

.20 

C 

42 

30 

66 

8 

1.78 

.37 

D 

42 

36 

32 

8 

1.10 

0.99 

A 

42 

36 

32 

8 

1.28 

.15 

B 

42 

36 

32 

8 

1.54 

.36 

C 

42 

36 

32 

8 

1.78 

.58 

D 

42 

36 

66 

8 

1.10 

0.99 

A 

42 

36 

66 

8 

1.28 

.15 

B 

42 

36 

66 

8 

.54 

.36 

C 

42 

36 

66 

8 

.78 

.58 

D 

48 

30 

32 

8 

.26 

0.88 

A 

48 

30 

32 

8 

.42 

.03 

B 

48 

30 

32 

8 

.71 

.20 

C 

48 

30 

32 

8 

.96 

.37 

D 

48 

30 

132 

8 

.26 

0.88 

A 

48 

30 

132 

8 

1.42 

1.03 

B 

48 

30 

132 

8 

1.71 

1.20 

C 

48 

30 

132 

8 

1.96 

1.37 

D 

48 

36 

32 

8 

1.26 

0.99 

A 

48 

36 

32 

8 

1.42 

1.15 

B 

48 

36 

32 

8 

1.71 

.36 

C 

48 

36 

32 

8 

1.96 

.58 

D 

48 

36 

132 

8 

1.26 

.99 

A 

48 

36 

132 

8 

1  .42 

.15 

B 

48 

36 

132 

8 

1.71 

.36 

C 

48 

36 

132 

8 

1.96 

.58 

D 

48 

42 

32 

8 

1.26 

.10 

A 

48 

.42 

32 

8 

1.  42 

.28 

B 

48 

42 

32 

8 

1.71 

.54 

C 

48 

42 

32 

8 

1.96 

.78 

D 

48 

42 

132 

8 

1.26 

.10 

A 

48 

42 

132 

8 

1.42 

.28 

B 

48 

42 

132 

8 

1.71 

.54 

C 

48 

42 

132 

8 

1.96 

.78 

D 

54 

36 

66 

8 

1.35 

0.99 

A 

54 

36 

66 

8 

1.55 

.15 

B 

54 

36 

66 

8 

1.90 

.36 

C 

54 

36 

66 

8 

2.23 

.58 

D 

54 

36 

132 

8 

1.35 

0.99 

A 

54 

36 

132 

8 

1.55 

.15 

B 

54 

36 

132 

8 

1.90 

.36 

C 

54 

36 

132 

8 

2.23 

.58 

D 

444 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE   NO.  11    (Continued). 
(Dimensions  in  Inches.) 


Nominal  I 

)iameter. 

E 

F 

V 

S 

TI 

T2 

Class. 

54 

42 

66 

8 

1.35 

1.10 

A 

54 

42 

66 

8 

1.55  . 

1.28 

A 

54 

42 

66 

8 

1.90 

1.54 

C 

54 

42 

66 

8 

2.23 

1.78 

D 

54 

42 

132 

8 

1.35 

1.10 

A 

54 

42 

132 

8 

1.55 

.28 

B 

54 

42 

132 

8 

1.90 

.54 

C 

54 

42 

132 

8 

2.23 

.78 

D 

54 

48 

66 

8 

1.35 

.26 

A 

54 

48 

66 

8 

1.55 

.42 

B 

54 

48 

66 

8 

1.90 

1.71 

C 

54 

48 

66 

8 

2.23 

1.96 

D 

54 

48 

132 

8 

1.35 

1.26 

A 

54 

48 

132 

8 

1.55 

1.42 

B 

54 

48 

132 

8 

1.90 

1.71 

C 

54 

48 

132 

8 

2.23 

1.96 

D 

60 

36 

66 

8 

1.39 

0.99 

A 

60 

36 

66 

8 

1.67 

1.15 

B 

60 

36 

66 

8 

2.00 

1.36 

C 

60 

36 

66 

8 

2.38 

1.58 

D 

60 

36 

132 

8 

1.39 

0.99 

A 

60 

36 

132 

8 

1.67 

1.15 

B 

60 

36 

132 

8 

2.00 

1.36 

C 

60 

36 

132 

8 

2.38 

.58 

D 

60 

42 

66 

8 

1.39 

.10 

A 

60 

42 

66 

8 

1.67 

.28 

B 

60 

42 

66 

8 

2.00 

.54 

C 

60 

42 

66 

8 

2.38 

.78 

D 

60 

42 

132 

8 

1.39 

.10 

A 

60 

42 

132 

8 

1.67 

.28 

B 

60 

42 

132 

8 

2.00 

.54 

C 

60 

42 

132 

8 

2.38 

.78 

D 

60 

48 

66 

8 

1.39 

.26 

A 

60 

48 

66 

8 

1.67 

.42 

B 

60 

48 

66 

8 

2.00 

.71 

C 

60 

48 

66 

8 

2.38 

.96 

D 

60 

48 

132 

8 

1.39 

.26 

A 

60 

48 

132 

8 

1.67 

.42 

B 

60 

48 

132 

8 

2.00 

.71 

C 

60 

48 

132 

8 

2.38 

.96 

D 

60 

54 

66 

8 

1.39 

.35 

A 

60 

54 

66 

8 

1.67 

.55 

B 

60 

54 

66 

8 

2.00 

.90 

C 

60 

54 

66 

8 

2.38 

.23 

D 

60 

54 

132 

8 

1.39 

.35 

A 

60 

54 

132 

8 

1.67 

.55 

B 

60 

54 

132 

8 

2.00 

.90 

C 

60 

54 

132 

8 

2.38 

2.23 

D 

PIPE  AND  MISCELLANEOUS  DATA. 


445 


TABLE   NO.    12.— SLEEVES. 
(Dimensions  in  Inches.) 


Nominal 
Diameter. 

Class. 

A 

B 

L 

O 

T 

4 

D 

1.50 

1.30 

10 

5.80 

0.65 

6 

D 

1.50 

1.40 

10 

7.90 

0.70 

8 

D 

1.50 

1.50 

12 

10.10 

0.75 

10 

D 

1.50 

1.60 

12 

12.20 

0.80 

12 

D 

1.50 

1.70 

14 

14.30 

0.85 

14 

A-B 

1.50 

1.70 

15 

16.20 

0.85 

14 

C-D 

1.50 

1.80 

15 

16.50 

0.90 

16 

A-B 

1.75 

1.80 

15 

18.50 

0.90 

16 

C-D 

1.75 

1.90 

15 

18.90 

1.00 

18 

A-B 

1.75 

1.90 

15 

20.60 

0.95 

18 

C-D 

1.75 

2.10 

15 

21.00 

1.05 

20 

A-B 

1.75 

2.00 

15 

22.70 

.00 

20 

C-D 

1.75 

2.30 

15 

23.10 

.15 

24 

A-B 

2.00 

2.10 

15 

26.90 

.05 

24 

C-D 

2.00 

2.50 

15 

27.40 

.25 

30 

A 

2.00 

2.30 

15 

32.80 

.15 

30 

B 

2.00 

2.30 

15 

33.10 

.15 

30 

C 

2.00 

2.60 

15 

33.50 

.32 

30 

D 

2.00 

3.00 

15 

33.80 

.50 

36 

A 

2.00 

2.50 

15 

39.00 

.25 

36 

B 

2.00 

2.80 

15 

39.40 

.40 

36 

C 

2.00 

3.10 

15 

39.80 

.60 

36 

D 

2.00 

3.40 

15 

40.20 

.80 

36 

A 

2.00 

2.50 

20 

39.00 

.25 

36 

B 

2.00 

2.80 

20 

39.40 

.40 

36 

C 

2.00 

3.10 

20 

39.80 

.60 

36 

D 

2.00 

3.40 

20 

40.20 

.80 

42 

A 

2.00 

2.80 

15 

45.30 

.40 

42 

B 

2.00 

3.00 

15 

45.60 

.50 

42 

C 

2.00 

3.40 

15 

46.20 

.75 

42 

D 

2.00 

3.80 

15 

46.70 

.95 

42 

A 

2.00 

2.80 

20 

45.30 

.40 

42 

B 

2.00 

3.00 

20 

45.60 

.50 

42 

C 

2.00 

3.40 

20 

46.20 

1.75 

42 

D 

2.00 

3.80 

20 

46.70 

1.95 

446 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE   NO.  12  (Continued). 
(Dimensions  in  Inches.) 


Nominal 
Diameter. 

Class. 

A 

B 

L 

0 

T 

48 

A 

2-.00 

3.00 

15 

51.60 

.50 

48 

B 

2.00 

3.30 

15 

51.90 

.65 

48 

C 

2.00 

3.80 

15 

52.50 

.95 

48 

D 

2.00 

4.20 

15 

53.10 

.20 

48 

A 

2.00 

3.00 

20 

51.60 

.50 

48 

B 

2.00 

3.30 

20 

51.90 

.65 

48 

C 

2.00 

3.80 

20 

52.50 

.95 

48 

D 

2.00 

4.20 

20 

53.10 

2.20 

54 

A 

2.25 

3.20 

15 

57.70 

1.60 

54 

B 

2.25 

3.60 

15 

58.20 

1.80 

54 

C 

2.25 

4.00 

15 

58.90 

2.15 

54 

D 

2.25 

4.40 

15 

59.50 

2.45 

54 

A 

2.25 

3.20 

20 

57.70 

1.60 

54 

B 

2.25 

3.60 

20 

58.20 

1.80 

54 

C 

2.25 

4.00 

20 

58.90 

2.15 

54 

D 

2.25 

4.40 

20 

59.50 

2.45 

60 

A 

2.25 

3.40 

15 

63.90 

1.70 

60 

B 

2.25 

3.70 

15 

64.50 

1.90 

60 

C 

2.25 

4.20 

15 

65.30 

2.25 

60 

D 

2.25 

4.70 

15 

65.90 

2.60 

60 

A 

2.25 

3.40 

20 

63.90 

1.70 

B 

2.25 

3.70 

20 

64.50 

1.90 

C 

2.25 

4.20 

20 

65.30 

2.25 

D 

2.25 

4.70 

20 

65.90 

2.60 

PIPE  AND  MISCELLANEOUS  DATA. 


447 


A  and  B  as  tabulated  in  Table  No.  1. 
£  =  2.50"  for  12"  to  24"  incl. 
X=1.25"  for  12"  to  24"  incl. 
Y=1.62"  for  12"  to  24"  incl. 


G  =  3.00"  for  30"  to  60"  incl. 
X=1.50"  for  30"  to  60"  incl. 
Y=2.00"  for  30"  to  60"  incl. 


TABLE   NO.   13.— CAPS. 
(Dimensions  in  Inches.) 


Nominal 
Diameter 

D 

O 

H 

T 

M 

K 

Z 

R 

Class. 

4 

4.0 

5  7 

4  10 

0.60 

D 

6 

4.0 

7.8 

4.15 

0.65 

D 

8 

4.0 

10.0 

4.75 

0.75 

.... 

D 

10 

4.0 

12.1 

4.75 

0.75 

1.50 

6.75 

.... 

16.2 

D 

12 

4.0 

14.2 

4.75 

0.75 

1.75 

0.75 

.... 

18.7 

D 

14 

4.0 

16.1 

4.90 

0.90 

1.90 

0.75 

22.4 

A-B 

14 

4.0 

16.45 

4.90 

0.90 

1.90 

0.75 

22.4 

C-D 

16 

4.0 

18.4 

5.00 

1.00 

2.00 

0.75 

27.0 

A-B 

16 

4.0 

18.8 

5.00 

.00 

2.00 

0.75 

27.0 

C-D 

18 

4.0 

20.5 

5.00 

.00 

2.00 

1.00 

32.0 

A-B 

18 

4.0 

20.92 

5.00 

.00 

2.00 

1.00 

.... 

32.9 

C-D 

20 

4.0 

22.6 

5.00 

.00 

3.00 

1.00 

1.25 

18.2 

A-B 

20 

4.0 

23.06 

5.00 

.00 

3.00 

1.00 

1.50 

18.2 

C-D 

24 

4.0 

26.8 

5.25 

.05 

3.50 

1.00 

1.30 

23.5 

A-B 

24 

4.0 

27.32 

5.25 

.05 

3.50 

1.00 

1.55 

23.5 

C-D 

448 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


TABLE   NO.  13  (Continued). 
(Dimensions  in  Inches.) 


Nominal 
Diam. 

D 

O 

H 

T 

M 

K 

z 

R 

Class. 

30 

4.5 

32.74 

5.75 

.15 

3.50 

.15 

1.30 

34.8 

A 

30 

4.5 

33.00 

5.75 

.15 

3.50 

.15 

1.50 

34.8 

B 

30 

4.5 

33.40 

5.75 

.15 

3.50 

.15 

1.70 

34.8 

C 

30 

4.5 

33.74 

5.75 

.15 

3.50 

.15 

1.90 

34.8 

D 

36 

4.5 

38.96 

6.00 

.25 

4.00 

.25 

1.63 

44.0 

A 

36 

4.5 

39.30 

6.00 

.30 

3.95 

.25 

1.88, 

44.0 

B 

36 

4.5 

39.70 

6.00 

.35 

3.90 

.25 

2.08 

44.0 

C 

36 

4.5 

40.16 

6.00 

.40 

3.85 

.25 

2.30 

44.0 

D 

42 

5.00 

45.20 

7.00 

1.40 

4.00 

.40 

2.00 

63.5 

A 

42 

5.00 

45.50 

7.00 

1.50 

3.90 

.40 

2.25 

63.5 

B 

42 

5.00 

46.10 

7.00 

1.60 

3.80 

1.40 

2.55 

63.5 

C 

42 

5.00 

46.58 

7.00 

1.70 

3.70 

1.40 

2.80 

63.5 

D 

48 

5.00 

51.50 

7.00 

1.70 

4.00 

1.50 

2.10 

76.5 

A 

48 

5.00 

51.80 

7.00 

1.90 

3.80 

1.50 

2.40 

76.5 

B 

48 

5.00 

52.40 

7.00 

2.00 

3.70 

1.50 

2.70 

76.5 

C 

48 

5.00 

52.98 

7.00 

2.10 

3.60 

1.50 

3.00 

76.5 

D 

54 

5.5 

57.66 

7.5- 

1.90 

4.50 

1.50 

2.20 

82.0 

A 

54 

5.5 

58.10 

7.5 

2.00 

4.40 

1.50 

2.50 

82.0 

B 

54 

5.5 

58.80 

7.5 

2.10 

4.30 

1.50 

2.80 

82.0 

C 

54 

5.5 

59.40 

7.5 

2.20 

4.20 

1.50 

3.10 

82.0 

D 

60 

5.5 

63.80 

7.5 

2.00 

4.50 

1.50 

2.30 

99.0 

A 

60 

5.5 

64.40 

7.5 

2.10 

4.40 

1.50 

2.60 

99.0 

B 

60 

5.5 

65.20 

7.5 

2.20 

4.30 

1.50 

2.90 

99.0 

C 

60 

5.5 

65.82 

7.5 

2.30 

4.20 

1.50 

3.20 

99.0 

D 

--L— • 

3  RIBS  SPIGOT  fee/VD  2.  RIBS 

E  —  actual  outside  diameter,  Table  No.  1. 

TABLE   NO.  14.— PLUGS. 
(Dimensions  in  Inches.) 


Nominal 
Diameter. 

L 

M 

Number 
of  Ribs. 

TI 

T2 

T3 

Class. 

4 

5.5 





0.50 

0.40 

0.20 

D 

6 

5.5 

f 

.... 

0.60 

0.40 

0.20 

D 

8 

5.5 

2.0 

2 

0.60 

0.40 

0.20 

D 

10 

6.0 

2.0 

2 

0.70 

0.50 

0.20 

D 

12 

6.0 

2.0 

2 

0.75 

0.50 

0.20 

D 

14 

6.0 

2.0 

2 

0.70 

0.50 

0.20 

A-B 

14 

6.0 

2.0 

2 

0.75 

0.50 

0.20 

C-D 

16 

6.5 

2.0 

3 

0.70 

0.50 

0.30 

A-B 

16 

6.5 

2.0 

3 

0.80 

0.60 

0.30 

C-D 

18 

6.5 

2.5 

3 

0.75 

0.60 

0.30 

A-B 

18 

6.5 

2.5 

3 

0.85 

0.60 

0.30 

C-D 

20 

6.5 

2.75 

3 

0.85 

0.60 

0.30 

A-B 

20 

6.5 

2.75 

3 

1  .00 

0.60 

0.30 

C-D 

PlPEAND  MISCELLANEOUS  DATA. 


449 


/"»"  |»-_ 


TABLE   NO.  15.— BELL  PLUG. 
(Dimensions  in  Inches.) 


Nom. 
Diam. 

Class. 

A 

B 

E 

J 

K 

L 

M 

N 

I 

T 

24 

A-B 

25.95 

25.8 

8 

4.5 

2.5 

2.25 

5.00 

2.25 

50 

0.89 

24 

C-D 

26.45 

26.32 

8 

4.5 

2.5 

2.25 

5.00 

2.25 

50 

1.16 

30 

A 

31.86 

31.74 

8 

4.5 

2.62 

2.25 

5.25 

2.5 

64 

0.88 

30 

B 

32.12 

32.00 

8 

4.5 

2.62 

2.25 

5.25 

2.5 

64 

.03 

30 

C 

32.52 

32.40 

8 

4.5 

2.62 

2.25 

5.25 

2.5 

64 

.20 

30 

D 

32.86 

32.74 

8 

4.5 

2.62 

2.25 

5.25 

2.5 

64 

.37 

36 

A 

38.08 

37.96 

8 

5.75 

3.12 

2.25 

6.25 

2.75 

84 

0.99 

36 

B 

38.42 

38.30 

8 

5.75 

3.12 

2.25 

6.25 

2.75 

84 

.15 

36 

C 

38.82 

38.70 

8 

5.75 

3.12 

2.25 

6.25 

2.75 

84 

.36 

36 

D 

39.28 

39.16 

8 

5.75 

3.12 

2.25 

6.25 

2.75 

84 

.58 

42 

A 

44.32 

44.20 

9 

6.25 

3.37 

2.25 

6.75 

2.87 

100 

.10 

42 

B 

44.62 

44.50 

9 

6.25 

3.37 

2.25 

6.75 

2.87 

100 

.28 

42 

C 

45.22 

45.10 

9 

6.25 

3.37 

2.25 

6.75 

2.87 

100 

1.54 

42 

D 

45.70 

45.58 

9 

6.25 

3.37 

2.25 

6.75 

2.87 

100 

1.78 

48 

A 

50.62 

50.50 

9 

6.75 

3.62 

2.25 

7.25 

3.00 

120 

1.26 

48 

B 

50.92 

50.80 

9 

6.75 

3.62 

2.25 

7.25 

3.00 

120 

1.42 

48 

C 

51.52 

51.40 

9 

6.75 

3.62 

2.25 

7.25 

3.00 

120 

1.71 

48 

D 

52.10 

51.98 

9 

6.75 

3.62 

2.25 

7.25 

3.00 

120 

1.96 

54 

A 

56.78 

56.66 

9 

7.25 

3.87 

2.25 

7.75 

3.12 

140 

1.35 

54 

B 

57.22 

57.10 

9 

7.25 

3.87 

2.25 

7.75 

3.12 

140 

1.55 

54 

C 

57.92 

57.80 

9 

7.25 

3.87 

2.25 

7.75 

3.12 

140 

1.90 

54 

D 

58.52 

58.40 

9 

7.25 

3.87 

2.25 

7.75 

3.12 

140 

2.23 

60 

A 

62.92 

62.80 

9 

7.75 

4.12 

2.25 

8.25 

3.25 

160 

1.39 

60 

B 

63.52 

63.40 

9 

7.75 

4.12 

2.25 

8.25 

3.25 

160 

1.67 

60 

C 

64.32 

64.20 

9 

7.75 

4.12 

2.25 

8.25 

3.25 

160 

2.00 

60 

D 

64.94 

64.82 

9 

7.75 

4.12 

2.25 

8.25 

3.25 

160 

2.38 

450 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


U-          -J 


TABLE   NO.  16.— OFF-SETS. 
(Dimensions  in  Inches.) 


Nominal 
Diameter. 

N 

5 

K 

L 

R 

T 

Class. 

4 

'     2 

10 

13.85 

35.85 

8 

0.52 

D 

6 

2 

10 

24.25 

46.25 

14 

0.55 

D 

8 

2 

10 

26.00 

48.00 

15 

0.60 

D 

10 

2 

10 

27.70 

49.70 

16 

0.68 

D 

12 

2 

10 

29.45 

51.45 

17 

0.75 

D 

14 

2 

10 

31.20 

53.20 

18 

0.66 

A-B 

14 

2 

10 

31.20 

53.20 

18 

0.82 

O-D 

16 

2 

10 

32.90 

54.90 

19 

0.70 

A-B 

16 

2 

10 

32.90 

54.90 

19 

0.89 

C-D 

20-  H*  BOUT* 

Hov.es 


TABLE   NO.  17.— MANHOLE   PIPES. 

(Dimensions  in  Inches.) 


Norn. 
Diam. 

I 

N 

T 

Class. 

Norn. 
Diam. 

L 

N 

T 

Class. 

30 

17 

21 

0.88 

A 

48 

17 

30 

1.26 

A 

30 

17 

21 

.03 

B 

48 

17 

30 

1.42 

B 

30 

17 

21 

.20 

C 

48 

17 

30 

1.71 

C 

30 

17 

21 

.37 

D 

48 

17 

30 

1.96 

D 

36 

17 

24 

0.99 

A 

54 

19 

33 

.35 

A 

36 

17 

24 

.15 

B 

54 

19 

33 

.55 

B 

36 

17 

24 

.36 

C 

54 

19 

33 

.90 

G 

36 

17 

24 

.58 

D 

54 

19 

33 

.23 

D 

42 

17 

27 

.10 

A 

60 

21 

36 

.39 

A 

42 

17 

27 

.28 

B 

60 

21 

36 

.67 

B 

42 

17 

27 

.54 

C 

60 

21 

36 

2.00 

C 

42 

17 

27 

.78 

D 

60 

21 

36 

2.38 

D 

PIPE  AND  MISCELLANEOUS  DATA. 


451 


NOTE  REGARDING  LUGS  ON  BRANCHES. 

Lugs  of  the  form  and  dimensions  given  in  the  preceding  tables  are  to  be 
placed  on  the  bells  of  side  outlets  on  all  branches,  on  outlets  12  inches  in 
diameter  and  larger  when  desired. 

NUMBER  AND   WEIGHTS   OF   LUGS   ON   OUTLETS   OF   DIFFERENT  SIZES. 


Diameter 
of  Outlet, 
Inches. 

No.  of  Pairs 
of  Lugs. 

Weight  of 
Lugs  on  One 
Bell,  Lbs. 

Diameter  of  Outlet, 
Inches. 

No.  of  Pairs 
of  Lugs. 

Weight  of 
Lugs  on  One 
Bell,  Lbs. 

12 

4 

32 

36 

6 

80 

14 

4 

32 

42 

8 

111 

16 

6 

56 

48 

8 

114 

18 

6 

56 

54  Class  A  and  B 

8 

126 

20 

6 

56 

54     "     C    "    D 

8  i 

134 

24 

6 

56 

60     "     A    "    B 

8  , 

129 

30 

6 

80 

60     "     C    "    D 

8  I 

137 

! 

Two  pairs  of  lugs  to  be  placed  on  the  vertical  axis  of  eachibell,  the  others 
to  be  spaced  at  equal  distances  around  the  circumference. 

If  branches  are  made  without  lugs,  the  standard  weighjts  given  in  the 
table  should  be  increased  in  accordance  with  the  weights  giv^n  above. 

A  METHOD  OF  "  CUTTINQ-IN "  SPECIALS. 

Made  in  4"  to  16"  diameters,  inclusive,  and  especially  desig- 
nated for  use  where  it  is  necessary  to  cut  a  street  main  for  set- 


Cut  A. 


ting  an  extra  hydrant,  the  opening  of  a  new  street,  or  for  the 
introduction  of  any  other  large  service. 


Cat  B. 


The  above  cuts  illustrate  the  advantage  of   the  "Cutting-in" 
Special,  one  end  of  which  is  enlarged  back  of  the  bell,  and  with 


452 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


its  face  made  slightly  oblique  to  the  axis  of  the  Special.  Thus 
it  is  readily  inserted  as  shown  and  necessitates  but  two  joints. 
At  the  back  of  the  bell  and  parallel  to  its  face  there  is  a  projec- 
tion or  rib  which  fits  the  main  pipe  and  forms  a  stop  for  the  yarn. 
The  Special  is  so  made  as  to  be  adapted  to  varying  thicknesses 
of  pipes  and  presents  no  difficulty  in  making  up. 

TABLE   OF  STANDARD   SIZES,   CUTTING-IN   TEES. 


Diameter  in 
Inches. 

Laying  Length 
in  Inches. 

Approximate 
Weight  in  Lbs. 

Will  take  Pipe  of 

Inside  Diameter, 

Thickness, 

Inches. 

Inches. 

3X  3 

16 

90 

3 

4X  4 

19 

100 

4 

&to& 

6X  6 

21 

190 

6 

|       f 

8X  8 

23 

290 

8 

10X10 

24 

380 

10 

JL         a. 

12X12 

24 

580 

12 

X         I 

14X14 

31 

780 

14 

*         tt 

16X16 

31 

950 

16 

i          1 

Side  outlets  of  different  diameter  than  main  run,  to  order  on 


Among  the  advantages  in  the  use  of  this  Special  are  diminished 
excavations,  saving  in  joints  and  labor,  absence  of  holding  and 
blocking  up  of  pieces,  variation  of  an  inch  or  two  in  length  of 
piece  cut  out  without  causing  trouble,  and  lessened  length  of  time 
the  water  needs  to  be  shut  off.  In  addition,  the  "Cutting-in" 
Special  may  be  used  as  an  ordinary  special  if  necessary,  and  where 
there  is  any  uncertainty  as  to  the  location  of  side  streets,  it  is 
cheaper  to  make  the  work  continuous  and  " cut-in"  branches  with 
this  Special  as  required. 

There  are  also  SHORT  LENGTHS  OF  PIPE  with  the  PATENTED  BELL 
and  a  SPIGOT  or  with  the  PATENTED  BELL  and  an  ORDINARY  BELL 
END.  Where  a  change  of  grade  or  alignment  is  not  sufficient  to 
require  a  curved  pipe,  this  form  of  short  pipe  admirably  answers 
the  purpose.  With  them  also  a  break  can  be  repaired  without  a 
sleeve  with  the  least  excavation  and  with  but  one  extra  joint. 

Under  ordinary  circumstances,  however,  the  author  recommends 
the  method  illustrated  in  Cut  A. 


PIPE   AND  MISCELLANEOUS  DATA.  453 

FLEXIBLE=JOINT  PIPE. 

Made  in  Lengths  to  Lay  12  Feet. 

The  joint  A  is  that  usually  employed,  and  admits  of  the  lead 
gasket  moving  upon  the  interior  surface  of  the  bell,  which  is  care- 
fully machined.  This  design  is  sometimes  modified  by  adding 
one  or  more  lead  grooves  upon  the  spigot  end. 


A.  Bell  End,  Machined  Inside. 


The  design  C  is  a  more  expensive  joint,  intended  for  the  larger 
size  of  pipe,  especially  when  they  are  used  for  conveying  water 
under  considerable  pressure.  This  joint  has  a  split  retaining 
ring  or  collar  bolted  to  the  hub,  as  shown,  forming  a  very  secure 


FLEXIBLE-JOINT  PIPE. 
(Weights  are  approximate  only.) 


Inside 
Diameter 
of  Pipe, 
Inches. 

Thickness 
of  Shell 
in  Inches. 

Weight 
per 
Length, 
Lbs. 

Lead 
per 
Joint, 
Lbs. 

Inside 
Diameter 
of  Pipe, 
Inches. 

Thickness 
of  Shell 
in  Inches. 

Weight 

T  peiY 

Length, 

Lbs. 

Lead 
per 
Joint, 
Lbs. 

4 

A 

350 

10 

16 

ft 

2190 

77 

4 

A 

280 

10 

16 

ft 

1660 

77 

6 

1 

550 

15 

18 

1 

2640 

93 

6 

440 

15 

18 

« 

1900 

93 

8 

5 

730 

21 

20 

3220 

112 

8 

I 

590 

21 

20 

li- 

2560 

112 

10 

ft 

1000 

28 

24 

ls 

'  4020 

144 

10 

& 

830 

28 

24 

« 

3440 

144 

12 

H 

1410 

38 

30 

11 

6190 

181 

12 

f 

1100 

38 

30 

1 

4870 

181 

14 

i 

1770 

64 

36 

If 

8800 

250 

14 

ft 

1450 

64 

36 

l| 

6770 

250 

454  AMERICAN  GAS-ENGINEERING  PRACTICE. 

connection.  For  large  diameters,  these  C  joints  made  in  short 
lengths  may  be  used  for  convenience  in  handling  or  in  connection 
with  a  line  partly  made  up  of  ordinary  bell-and-spigot  pipe,  though 
usually  resulting  in  extra  expense;  full-length  pipe,  necessitating 
fewer  joints,  are  generally  to  be  preferred. 

In  standard  flexible- joint  pipe  the  maximum  deviation  per- 
mitted by  the  joint  is  10°,  taken  in  any  direction. 

In  selecting  the  thickness  of  pipe  for  a  submerged  line,  the 
internal  pressure  under  which  it  will  be  in  service  is  seldom  the 
determining  factor,  as  ample  allowance  should  be  made  to  mini- 


C.  Spigot  End,  Machined  Outside  and  Fitted  with  Retaining  Ring  or  Collar, 

Complete  with  Bolts. 

mize  the  risk  of  breakage  in  laying,  and  to  withstand  external 
shocks  from  floating  ice  or  other  objects.  The  enlarged  hubs 
naturally  add  materially  to  the  weight  of  flexible-joint  piping; 
and  the  thicknesses  and  weights  suggested  in  the  table  may  be 
taken  as  in  line  with  good  practice. 

Made  regularly  in  lengths  to  lay  about  twelve  (12)  feet. 

A  full  assortment  of  flexible-joint  pipe  of  design  A,  and  of 
about  the  weights  given  in  the  table,  usually  in  stock. 

Design  C  to  order  only. 

Short  sections,  design  C,  of  sizes  20"  diameter  and  upward, 
for  laying  between  ordinary  pipe,  to  order. 

Inquiries  should  state  the  approximate  quantity  of  pipe,  the 
thickness  of  shell,  or  weight  per  length,  and  time  and  place  of 
delivery  desired. 


PIPE  AND  MISCELLANEOUS  DATA. 


455 


Knuckle-joints. 

Made  with  ordinary  bell,  bell-and-spigot,  or  flanged  ends.  These  short 
sections  are  used  in  making  river  crossings  in  connection  with  regular  flange 
or  bell-and-spigot  pipe.  The  larger  sizes  with  cast-iron  or  steetriveted 
flange  pipe  make  an  excellent  arrangement  for  intakes  with  floating  screen. 
Flanged  joints  are  drilled  only  to  order. 

KNUCKLE-JOINTS,  SHORT  SECTIONS. 
STYLE  A. 


Laying  Length. 

Approximate  Weight  in  Lbs. 

Inside 

Thick- 

Outside 

Joint  with       T«:~* 

Diameter 

ness  of 

Diameter 

Bell  or 

«  umuv 

with. 

of  Pipe, 
Inches. 

Pipe, 
Inches. 

of  Flange, 
Inches. 

Bell 
Ends, 
Inches. 

Bell  and 
Spigot, 
Inches. 

Flange 
Ends, 
Inches. 

Bell-and- 
spigot 
Ends, 
without 
Lead. 

Flange 
Ends, 
without 
Lead. 

Lead 
per 
Joint. 

4 

A 

9 

10* 

22f 

10* 

100 

80 

10 

6 

11 

11* 

23* 

Hi 

140 

100 

15 

8* 

ft 

13* 

12* 

131 

220 

160 

21 

10 

1 

16 

26| 

14* 

310 

230 

28 

12 

tt 

19 

16* 

28 

16 

440 

350 

38 

14 

21 

17f 

29| 

17f 

580 

460 

64 

16 

1 

23  £ 

19* 

3H 

19* 

780 

640 

77 

18 

*l 

25 

21* 

33  1 

21  i 

990 

800 

93 

20 

i 

27* 

23 

35 

23 

1280 

1050 

112 

24 

i^ 

32 

25  £ 

37* 

25* 

1700 

1410 

144 

30 

i* 

38J 

29 

41 

29 

2720 

2300 

181 

36 

45f 

32* 

44* 

32* 

4100 

3570 

250 

456 


AMERICAN  GAS-ENGINEERING  PRACTICE. 


Connecting  Mains. — In  a  paper  upon  this  subject  Mr.  Forstall 
advocates  the  following  table  to  determine  the  size  of  connections 
and  the  method  of  making  same: 


NEW  MAIN  TO  EXISTING  MAINS. 


Size  of 
New 
Mains. 

Size  of  Existing  Mains. 

30  in. 

24  in. 

20  in. 

16  in. 

12  in. 

8  in. 

6  in. 

4  in. 

4  inch 

6  inch 
8  inch 
12  inch  I 
16  inch  f 
20  inch 
24  inch 
30  inch 

Saddle  Pee 
or  Hat  Fig. 

Insert 
Branch 

Saddle 
Piece 

Insert 
Branch 

Saddle  P'ce 
Split  si'  ves 

Insert 
Branch 

Insert 
Branch 

Insert 
Branch 

Insert 
Branch 

Insert 
Branch 

Insert 
Branch 

Tools  for  Laying  Cast=iron  Pipes. — After  the  material,  in- 
cluding pipe  and  fittings,  yarn,  cement,  or  lead,  has  been  ordered, 
the  following  tools  will  be  needed  for  the  work.  The  number  of 
laborers  required  and  the  tools  needed  will,  of  course,  vary  with 
the  size  and  length  of  the  main  to  be  laid.  If  a  considerable  main, 
say  4,  6,  or  12  inch,  to  each  fifty  laborers  two  pipe  handlers  in 
trench,  one  yarner,  four  calkers,  one  lead-jointer,  and  one  blocking 
man  will  be  sufficient  to  start  the  men. 

1  tapping-machine,  I"  to  2"  taps. 
4  calking-hammers. 

2  Trimo  wrenches,  18"  and  24". 

4  8-pound  striking-hammers  for  use  with  dog-chisel  in  cutting 
cast-iron  pipes. 

2  15"  monkey-wrenches. 

3  dog-chisels  with  handles. 
1  2-lb.  machinists'  hammer. 

1  12-lb.  sledge-hammer. 

2  paving-hammers. 

4  sets  calking-tools — 8  pieces  to  the  set. 
6  lead-chisels. 

4  split-chisels. 
4  yarning-irons. 
6  cold-chisels. 
6  diamond-points. 
2  5-ft.  crowbars. 
10  railroad  tamping-bars. 
6  4"  trowels. 

1  10"  trowel. 

2  18"  spirit-levels. 
1  iron  oil-can. 


PIPE  AND  MISCELLANEOUS  DATA.  457 

1  hand-saw. 

1  2-man  saw. 

2  axes. 

2  dozen  street-lanterns  with  red  globes. 
1  dozen  iron-plug  dirt-pounders. 
1  5-gallon  kerosene-oil  can. 
1  15X30  galvanized-iron  cement  can. 
1  100-ft.  metallic  tape  measure. 
1  12-ft.  pipe-scraper  for  scraping  dirt  out  of  pipe. 
1  wheelbarrow. 
A  street-brooms. 

1  salamander  furnace  with  lead  kettle  for  same. 

2  small  lead  kettles  for  pouring  joints. 
2  pieces  Manila  rope  30  feet  long. 

2  tripods.  A  derrick  or  crabs. 

2  Yale  &  Town  chain-block,  or  similar  make. 

4  tunne ling-shovels. 
90  railroad-picks. 
40  pick-handles. 

60  sharp-nose  D-handle  shovels. 

10  flat-nose   D-handle   shovels   for  bottom   work   and   street- 
cleaning. 

1  lot  assorted  gas-bags.     These  should  never  be  left  around  in 
the  tool-box,  but  should  be  called  for  as  needed. 

6  12X18X4"  galvanized-iron  cement  pans. 

4  galvanized  water  buckets. 

4  pairs  rubber  gloves. 

Wooden  plugs  or  stoppers  to  fit  various  size  mains. 

2  tool-boxes — 1  for  lighter  material  and  1  for  picks,  shovels, 
crowbars,  sledges,  etc. 

1  or  more  three-wheel  pipe-cutters  to  cut  from  f  "  to  2". 

1  threading-machine  }"  to  1",  or  Beaver  die  stock  and  portable 
vise. 

2  slings  of  rope. 

6  forks  (for  separating  gravel). 

2  sets  of  Lawn  horseshoes  for  tamping  (discretionary). 

1  set  C.  I.  pipe-cutters,  Hall  or  Rodfield  type,  with  extra  links. 

Under  some  circumstances  on  long  lines  a  pneumatic  hammer, 
the  compressor  being  driven  by  portable  gasoline  engine  and  the 
hammer  fitted  with  calking-tools,  may  be  used  to  advantage. 

Wrought=iron  Low-pressure  Mains. — In  laying  wrought- 
iron  mains  the  preparation  to  be  made  is  the  same  as  for  cast-iron 
mains,  with  the  exception  that  it  is  not  customary  in  laying  low- 
pressure  natural-gas  mains  to  make  any  provision  for  laying  to 
grade.  There  is,  of  course,  some  difference  in  the  tools  required 


458  AMERICAN  GAS-ENGINEERING  PRACTICE. 

for  the  work.  In  addition  to  the  ordinary  tools  required  by  the 
laborers  for  digging  the  trench,  etc.,  the  following  tools  will  be 
needed  by  the  pipe-layers. 

2  sets  stocks  and  adjustable  (retreating  dies)  for  rechasing  and 
cleaning  threads. 

Swabs  for  cleaning  out  the  different-size  mains. 

2  pipe- jacks  and  boards. 

4  pairs  of  tongs  for  each  size  main  to  be  laid. 

2  sets  of  chain- tongs. 
Diamond-point  chisels. 
Cape-chisels. 
Machinists'  hammers. 
Crowbars. 

1  large  air-pump  (may  be  power  driven)  and  gage. 

The  lay -tongs  are  pipe-tongs  made  for  this  kind  of  work.  They 
are  very  long,  are  built  heavy,  and  the  bit  is  held  in  place  by  a 
wedge,  and  having  four  sides  can  be  turned  and  a  fresh  biting 
edge  obtained.  Chain-tongs  are  best  for  fittings. 

Where  the  work  is  extensive  and  a  long  line  of  pipe  to  be  run, 
a  power  winch,  with  two  hand-wheels  and  a  chuck  for  holding  the 
pipe,  may  be  used  to  advantage  for  screwing  home  pipe,  the  joint 
being  started  by  hand  and  several  lengths  being  screwed  at  one 
operation. 

Blasting. — Where  it  is  necessary  to  blast  in  close  quarters,  or 
where  there  is  any  danger  from  flying  missiles,  this  danger  can  be 
obviated  or  reduced  to  the  minimum  by  including  in  the  equipment 
a  heavy  rope  net  under  which  is  placed  a  lighter  rope  net,  the  sides 
being  weighed  down  by  heavy  timbers  and  stones.  The  mesh  of 
the  nets  should  not  exceed  three  to  four  inches  and  the  net  laid 
slack. 

Service  Gang  and  Tools. — A  service  gang  usually  consists 
of  one  fitter  and  his  helper  and  three  to  six  laborers.  A  competent 
fitter  may  be  foreman  of  this  gang.  In  addition  to  the  service 
wagon  containing  pipe-lengths,  fittings,  etc.,  and  a  portable  vise, 
either  with  bench  or  attachable  to  a  post,  the  equipment  usual 
for  each  gang  is: 

3  sharp-nose  D-handle  shovels. 

1  set  adjustable  stock  and  dies,  Beaver  type. 

1  ratchet  stock  and  dies,  for  trench  and  repair  work. 

1  long-handled  shovel  for  tunneling. 

4  railroad-picks  with  handles. 

2  steel  forks  for  separating  dirt  and  gravel. 
2  3'  6"  crowbars. 

1  street-broom. 

I  tapping-machine,  }"  to  2". 


PIPE  AND  MISCELLANEOUS  DATA.  459 

1  12-lb.  sledge. 

2  18"  and  124"  Trimo  wrenches. 

1  10"  Trimo  wrench. 

2  18"  wall-chisels. 

1  3-wheel  pipe-cutter  (with  extra  wheels)  for  trench. 

1  hatchet. 

1  wheel  pipe-cutter  for  vise  work. 

1  18"  bastard  file. 

1  2-lb.  machinist's  hammer. 

1  oil-can  and  oil. 

3  lanterns  and  red  globes,  1  oil-can  for  same. 
1  small  test-pump  and  gage. 

No  laboring  gang  should  be  allowed  to  assemble  upon  the  work 
without  proper  tool  and  supply  equipment,  as  enormous  delays 
frequently  occur,  due  to  the  lack  of  some  necessary  tool,  and  the 
cost  of  the  operation  is  correspondingly  increased. 

The  use  of  the  above  inventories  will  be  found  of  some  con- 
venience for  checking  up  the  equipment  prior  to  the  start  of  the 
day's  work.  Tool-books  containing  these  inventories  should  be 
maintained  and  the  equipment  checked  off  at  least  twice  a  day, 
at  which  times  either  the  tools  or  their  parts  should  be  in  evidence, 
or  the  workman  to  whom  issued  held  responsible. 

Haulage. — An  earth-cart  should  contain  1  cu.  yd. 

An  earth-wagon  (small  size)  1.5  cu.  yds. 

An  earth-wagon  (large  size)  3  cu.  yds. 

Wheelbarrow,  0.1  cu.  yd. 

One  single  load  of  earth=27  cu.  ft.  =  21  bushels. 

One  double  load  of  earth  =  54  cu.  ft. 

One  cu.  yd.  of  gravel  =  18  bu.  (in  the  pit). 

One  cu.  yd.  of  gravel  =  24  bu.  (when  dug). 

When  formed  into  embankments  gravel  sinks  J  in  height  and 
decreases  \  in  bulk. 

Earth  (well-drained)  will  stand  in  embankments  about  l\  to  1. 

(O'Connor.) 

Weight  of  Yarn. — In  making  lead  joints  for  cast-iron  mains 
the  weight  of  calking-yarn  necessary  is  about  as  follows: 

WEIGHT    OF    YARN    PER   JOINT. 


Diameter  Pipe,      Weight  of  Yarn, 

Inches.  Ounces. 

3  3  to  3} 

4  3J 
6  '  4f 
8  5} 

10  6J 


Diameter  Pipe,      Weight  of  Yarn, 

Inches.  Ounces. 
12  10 

16  12 

20  14J 

23  211 

30  22" 


460  AMERICAN  GAS-ENGINEERING  PRACTICE. 

Economic  Sizes  of  Purifying=boxes  (Newbiggin's  6th  Edition)  . 
—  "  Where  there  are  intended  to  be  four  purifiers  (what  we  term  the 
four-box  system),  three  always  in  action,  the  maximum  daily  (24- 
hour)  make  of  gas,  expressed  in  thousand  cubic  feet,  multiplied 
by  the  constant  0.6,  will  give  the  superficial  area  in  feet  for  each 
purifier."  Or  60  square  feet  of  area  in  each  box  per  100,000 
cubic  feet  make  per  24  hours. 

(Mr.  J  .  A.  P.  Crisfield,  representing  the  most  approved  American 
practice.) 

Assuming  a  time  contact  of  60  seconds  (oxide  of  iron), 

_n_  36007 
~ 


where  V  is  volume  of  oxide  in  cubic  feet  (between  inlet  of  first 
box  and  point  of  test);  R  equals  rate  of  "make  per  hour." 

This  "volume  of  oxide"  may  of  course  be  divided  by  any  num- 
ber necessary  to  determine  the  various  sizes  of  boxes  found  to  be 
convenient. 

Or  the  equation  may  be  simplified  to  read 


or  the  volume  of  oxide  between  the  inlet  of  the  purifiers  and  the 
completion  of  treatment  for  sulphureted  hydrogen  must  be  1/20 
of  the  rate  of  flow  of  gas  per  hour. 

This  rate  of  flow  should  be  based  upon  the  maximum  or  "peak" 
load  of  the  year's  output.  Due  allowance  should  of  course  be 
made  in  the  installation  of  boxes  for  an  increase  of  manufacture. 
It  is  also  based  upon  the  purification  of  carburetter  water-gas, 
and  should  be  increased  approximately  one-third  in  area  of  square 
feet  for  coal-gas. 

Mr.  CrisfiekTs  formula,  being  based  upon  an  equation  between 
cost  of  installation,  interest,  and  depreciation  of  apparatus  of 
boxes,  and  the  cost  of  labor  and  operation,  undoubtedly  consti- 
tutes the  highest  authority  for  American  engineers. 


SUBJECT-INDEX. 


Abel  flash-test  for  oil,  45 

Air,  compressed,  power  required,  225 

Air,  saturation  of,  by  aqueous  vapor, 

275,  279 

Analyses  of  steam-boiler  fuels,  325 
Analysis:  carbon  dioxide,  23 

carburetter  oil,  44 

fire-clay,  31 

sulphur  in  oxide,  86 
iodine  method,  87 

water-gas  scrubber  water*,  66 
Appliances,  gas:  industrial,  264 

lighting,  260 

ranges,  cooking,  249 
Aqueous  vapor  in  air,  275,  279 
Area  of  circles,  343,  358 
Asbestos  lining  for  range  ovens,  252, 

258 
Ash  in  fuel,  influence  on  value,  327 

Barometric   temperature   correction, 

276 

Barrel  calorimeter,  13 
Barring  for  gas  leaks,  162 
Barrus  throttling  calorimeter,  14 
Beaume  degrees  into  specific  gravity 

conversion,  286 
Blasting  of  water-gas  generator,  3 

pressure,  5 
Blowers  for  generator  blast,  4 

Sturtevant,  as  exhausters,  107 
Boyle's  law,  expansion  of  gases,  273 
Branch  main  connections,  456 
Brass  fittings,  red  and  yellow,  157 
Breaks  in  mains,  repairing,  166,  451 
Bueb    anthracene    naphthalene    sol- 
vent, 139 

Bunsen's   effusion   test    for   specific 
gravity,  281 


Burners:  gas-range,  250 
incandescent,  260 
open  flat-flame,  262 
tar,  water-gas,  62 

Calculation  by  logarithms,  354 
Calibration  of  the  Barrus  calorimeter, 

15 
Calorific  power  of  gases,  404 

calculation  of,  291 

Calorimeter,  Junker's  gas  and  oil,  292, 
297 

Simmance-Abady,  299 
Calorimetry  of  steam,  13 
Candle-power  and  heat  value,  261 

value  of  carburetter  oil,  48 
Capacity  of  consumer's  meters,  210 
Carbon  deposits  in  superheater,  54 
Carbon  dioxide:  analysis,  23 

coal,  equivalent  of,  in  flue-gas,  340 

water-gas  containing,  10,  22 
Carburetter  brickwork,  36 
Carburetter  oils:  analysis  of,  44 

comparison  of,  50 

pump  for,  41 

storage,  42 

supply,  39 
Carburetter,  operation  details,  51 

temperature,  49 

Cement  pipe-joints,  148,  152,  153 
Cements  and  fluxes  for  pipe,  248 
Checker-brick  spacing,  37 
Chimneys:  calculation  of  height,  332 

draught,  size,  capacity,  334,  336 
Chords  of  circle,  polygons,  353 
Circular  functions,  341,  343,  358,  359 
Circumference  of  circles,  343,  358 
Clinker,  generator,  6 
Coal:  anthracite,  for  generator,  20 
461 


462 


SUBJECT-INDEX. 


Coal:  size  of,  for  generator,  21 
Coating  services,  201 
Coke,  qualities  of  generator,  19 
Combustion   of   gases:   calculations, 
403,  409 

flat-flame  burners,  262 

temperatures,  302 
Complaint  meters,  212  > 
Composition  of  gases,  267,  268 
Compression  of  air,  table,  105 
Compression  of  gas:  analysis,  227 

candle-power  affected  by,  226 

condensation  due  to,  226 

volume  affected  by,  227 
Conductors  of  heat,  relative  values, 

308,  310 
Condensers,  water-gas,  67 

principle  of,  69 

surface  condensation,  68 

temperatures  in,  67 
Connections    to    consumers'  meters, 

211 

Consumption,  gas,  by  industrial  ap- 
pliances, 265 

Conversion  factors,  French-English, 
368 

compound  units,  370 

English  measures,  water,  375 

heat-units,  371 

temperature  scale,  306,  372 

weights  and  measures,  369,  406 
Correction,  volume,  for  temperature, 

215 

Corrosion  of  services,  protection,  201, 
203 

steel  services,  397 
Cost  of  main  laying,  168,  176 
Cox  computers  for  gas  flow,  143,  224 
Cutting-in  tee  for  cut  main,  451 
Cylindrical  vessels,  table  of  gallons, 
360 

Dimensions:  cast-iron  pipe  specials, 

199 

iron  and  steel  pipe,  204 
Distillation  data  for  carburetter  oil, 

47 

Dresser  pipe  coupling,  156 
Drill  and  tap,  numbers  for,  399 
Drips  on  high- pressure  mains,  160 

Efficiency:  gas  ranges,  249 

steam  flow  in  water-gas  generator, 

10 

Effusion  test  for  specific  gravity  of 
gases,  281 


Engine,  gas:  cause  of  pressure  pulsa- 
tions, 223 

installation  and  operation,  266 
Evaporation    of    water,    equivalent, 

411 

Excavating  trenches,  cost  of,  169 
Exhausters,  gas,  92 

capacity,  99 

dimensions,  100 

installation,  94 

operation  of,  94 
effect  of  altitude,  103 

power  required  for,  92,  103 

pressure,  high,  97 

revolutions  and  pressure ,  101 

slip  and  losses,  95,  96 
Expansion:  curves  for  steam,  320 

gases,  laws  of,  271 

liquids  and  metals,  309 

Fire-brick:  analysis,  31 

carburetter,  36 

checker,  spacing  of,  37 

properties  of,  27 

superheater,  37 

Fire-clay  for  brick,  properties  of,  29 
Fittings:,  brass,  red  and  yellow,  157 

flanged,  381 

Mueller  high-pressure,  205 

pressure,  high,  205 

service  pipe,  203 

weight  of  malleable  iron,  386 
Fixtures,  gas,  requirements,  238 
Flexible   pipe- joint,  ball-and-socket, 

453 
Flow  of  gas  in  pipes,  142,  231 

comparison  of  formulae,  235 

Cox  high- pressure  formula,  224 

Pole's  formula,  142,  232,  280,  377 

Robinson's  formula,  377 

through  orifices,  251 
Flow  of  water  in  pipe,  327,  329 
Flue-gas,  coal  equivalent  of  CO2  in, 

340 

Flues,  boiler-stack,  area  of,  337 
Forcing- jack  for  running  services,  203 
Freezing  up:  gas-holder  tanks,  124 

services,  prevention,  202 
French  and  English  units,  conversion 

of,  368 

Fuel  economizer,  Green  fuel,  132 
Fuels:  generator,  2,  19 

steam  raising,  325 

Gages,  pressure,  219 
Barrus  draught,  224 


SUBJECT-INDEX. 


463 


Gages,  differential,  St.  Louis,  221 

multiple  connections  for,  220 

Pitot  tube,  222 
Gallons:  cylinders,  table  of,  380 

in  box-like  vessels,  364 
Generator,  water-gas:  blast-pressure, 
26 

clinker,  6 

fuels  compared,  1,  2,  19 

linings,  19,  25,  27 

operation,  3,  17,  18 

safety  devices,  27 

steam  supply,  6 

Governors  for  gas  pressure,  218 
Grade  of  gas-mains,  144 
Green  fuel-economizer  132 

Heat  values:  boiler-fuels,  326 

calculation  of,  291 

candle-power  relation,  280 

combustion,  404,  408 

conductors,  comparative,  308 

insulation,  252 

radiation,  308 
from  pipe,  391 

units,  conversion,  306,  371 
Holders,  gas:  calculations,  127 

capacity  of,  127 

pressure  by,  122 

site  of  a,  130 

tanks,  124 

freezing,  prevention,  124 
patches  on,  125 

weighting  of,  123 

wind  pressure  on,  129 
Hydrometer    into    specific    gravity, 
conversion,  286 

Incandescent  gas-lighting,  260 
Inch,  fractions  of  an,  decimal  equiva- 
lents, 352 
Industrial  gas  appliances,  264 

consumption,  265 

gas-engines,  266 

operation,  264 

Joints,  pipe:  see  Pipe- joints. 
Junker's  gas-calorimeter,  292 

Latent  heat  of  steam,  311 
Laying  of  gas  mains,  143,  147 

cost  of;  172,  176 
Lead  in  pipe-joints,  145,  146,  150 

lead  wool,  180 
Lead  pipe,  weight  of,  389 
Leaks  in  gas-mains,  162 


Letheby's  globe  for  specific  gravity 
test,  2&3 

Lighting  appliances,  260 

Linear  expansion  of  metals,  coeffi- 
cients, 309 

Logarithms  of  convenient  constants, 

352 
numbers,  354 

Lunette  pyrometer,  polarizer,  305 

Lux  gas-balance  for  specific-gravity 
test,  285 

Mains,  gas:  breaks,  repairing,  166 

capacity,  142 

cost  of,  168 

subaqueous,  177 
taking  up,  177 

crosses,  designating,  179 

deposits,  161 

excavation  cost,  168 

gradient,  144 

joints:  see  Pipe-joints. 

laying,  pneumatic  tools,  143,  160 

leaks,  records  of,  162,  163 

loading  and  hauling,  168 

repair  work,  168 

service  connection,  163 

special  for  joining  break,  451 

specials,  182,  420 

stoppers,  167 

tools  for  laying,  456 

trenching,  cost  of,  168 
Mains,  high-pressure   gas:    anchors, 
160 

drips,  160 

joints,  154 

regulators,  159 

testing,  160 

valves,  159 
Mantle  burners,  260 
Mathematical  tables,  341 
Measurement:  gas,  standard  unit,  117 

generator  steam,  7 
Melting-points   of   metals,    Princeps 

alloys,  304 
Meters,    gas,    consumers':    capacity, 

210 
complaint,  212 

connections,  211 

installation  specifications,  237 

operation  of,  213 

Sprague,  214 

temperature  correction,  215 

testing  of,  209,  212,  215 
Meters,  gas,  station:  by- pass,  114, 

connections,  113 


464 


SUBJECT-INDEX. 


Meters,  operation  hints,  118 
rotary  type,  119 
sizes,  schedule  of,  112 
volume  correction  for,  115 

Meter,  generator-steam,  8 

Metric   system,  conversion   of,  368, 
406 

Mueller  high-pressure  fittings,  205 

Naphthalene:  deposits  in  pipes,  136 
preventing  deposits,  139 
properties  of,  135 
removal  from  pipes,  137,  161 
solution  in  benzine,  140 
test  for,  with  picric  acid,  141 

Oils:  gas-making,  comparison  of,  50 
grades  for  carburetter,  43 
specific-gravity  determination,  285 
storage  for  carburetter,  42,  52 
supply  for  carburetter,  39 

Oliphant's  formula,  flow  of  gas,  232 

Operation  of  water-gas  works,  131 
data  to  be  recorded,  132 

Ounces  pressure  converted  to  inches, 
228 

Oxide  of  iron:   preparation  for  puri- 
fication, 77 
revivification  of,  82 

Paint,  water-gas  tar,  59 

Palladium  chloride  test  for  leakage, 

163 

Patches  on  gas-holder  tanks,  125 
Photometer,  jet,  131 
Pipe:  capacity  for  gas  flow,  377 

connection  for  high-pressure,  208 

cost  of  handling,  168 

dimensions  of,  383 

radiating  surface  of,  391 

screw-threads  for,  382 

service-pipe  dimensions,  204 

specifications,  414 

standard  specials,  420 

subaqueous,  cost  of  laying,  177 

tools  for  laying,  456 

water-pipe,  cost  of  laying,  173 
Pipe  cement  and  fluxes,  248 
Pipe- joints:  ball-and-socket,  152, 153, 
453 

cement,  148,  152,  153 

comparison  of  various,  152 

coupling,  Dresser,  156 

dimensions,  199 

flanged,  380 

high- pressure,  154,  159 


Pipe-joints:  lead,  making  of,  150 

lead  wool,  180 

specifications,  145 

universal,  machined,  154 

yarn  required  for,  153,  459 
Piping,  house:  capacity  of,  247 

gas-engine,  247 

gas  ranges,  251 

installation,  244 

sizes  of  pipe  allowed,  240 

specifications,  236 

weight  of  pipe,  246 
Pitot  tube  for  measuring  gas  flow,  222 
Plates,  riveted  joints  for,  392 
Pneumatic  tools  for  cutting  mains, 

160 
Pole's  formula  for  gas  flow  in  pipes, 

142,  232,  280,  377 
Power  required  by  exhausters,  92 
Preheater  for  carburetter  oil,  40 
Pressure,  gas:  adequate,  216 

aqueous  vapor,  effect  of,  278,  279 

burner  pressure,  217 

gages,  charts,  219 

governors,  station,  street,  218 

holder,  pressure  thrown  by,  122 

ounces  to  inches,  conversion,  228 

Pitot  tube  for  measuring,  222 

pulsations,  gas-engine,  223 

regulators,  high- pressure,  159 

storage-tanks,  high-pressure,  229 

square-root  table,  280 
Pressure,  generator  blast,  5 
Pressure,  high,  gas-fittings,  205 
Pressure,  wind,  on  gas-holders,  129 
Princeps  alloys,  melting-points,  304 
Properties  of  gases,  267 
Pump,  water-gas  tar,  60 
Purification  practice,  72,  460 

analysis  of  spent  oxide,  86 

boxes,  size  of,  460 

calculations,  79 

capacity  of  boxes,  74 

grids,  Jaeger,  90 

lime,  preparation  of,  78 

material,  purifying,  74 

oxide  of  iron,  preparation,  77 

testing-boxes,  81 

Pyrometer,  blue-glass  optical,  Earn- 
shaw,  300 

Siemens,  311 

Radiation  of  heat,  308,  310 

surface  of  pipes,  391 
Ranges,  gas:  baking,  253 

burners,  250 


SUBJECT-INDEX. 


465 


Ranges,  care  of,  258 

cocks,  255 

combustion,  255 

essentials  in  selecting,  254 

gas  consumed,  253 

heat  insulation,  252 

piping,  251 

specifications,  259 

testing,  256 

Reactions  in  water-gas  generator,  23 
Receiving-tanks  for  compressed  gas, 

230 

Recipes,  248,  398 
Records  of  gas-mains,  163 
Reflection    of    heat    from    surfaces, 

relative,  310 

Regulation  of  gas  pressure,  216 
Removing  old  mains,  cost  of,  177 
Repairing  cements  for  generator,  26 
Revivification  of  iron  oxide,  82 

in  situ,  85 

Riveted  joints  for  plates,  392 
Robinson's  pressure  formula  for  gas 

flow,  142,  377 

Roots  of  numbers,  341,  357 
Rotary  station  gas-meter,  119 
Rules  for  house  piping,  236 

Saturated  steam,  properties  of,  323, 

324 
Schilling's  effusion  test   for  specific 

gravity,  282 

Screw-threads  for  bolts,  407 
Scrubbers,  water-gas:  operation,  64 

sprays,  65 

trays,  64 

water,  analysis,  66 
Services,  200 

coating,  201 

connections,  163,  208 

fittings,  high-pressure,  203 

forcing-jack  for  running,  203 

freezing,  202 

stoppages,  202 

tapping,  200 

tools  for  laying,  458 
Siemens  pyrometer,  311 
Simmance-Abady  gas-ealorimeter,299 
Sizes  of  pipe  for  house  piping.  240, 

242,  247 
Slip  in  gas-exhausters,  96 

losses  due  to,  98 
Solubility  of  gases  in  water,  270 
Spacing  of  checker-brick,  37 
Special    pipe- joint,    ball-and-socket, 
453 


Specials,     pipe:    cutting-in,    special 

form,  451 

designating  of,  179 
gas-main,  182 

Specifications:  cast-iron  pipe,  414 
house  piping,  236 
pipe- joint,  145 
Specific  gravity:  gas,  determination, 

281 

oils,  determination,  285 
square  roots  of,  280 
Specific  heat:  defined,  287 
gases,  constant  pressure,  288 
constant  volume,  290 
calculating  mean,  288 
solids  and  liquids,  289,  290,  405 
steam,  318 
Sprague  meter,  214 
Sprays  for  water-gas  scrubbers,  65 
Square  roots  of  pressure  and  gravity, 

280 
Squares,  cubes,  etc.,  of  numbers,  341, 

357 
Standards:  pipe  specials,  420 

unit  of  gas  volume,  117 
Steam:  calorimetry  of,  13 

equivalent  evaporation  of  water, 

expansion  curves,  320 

formulae  for,  322 
generator,  meter  to  measure,  7 
rate  of  flow  into,  9 
supply,  6 

latent  heat  of,  311 
pressure,  temperature,  volume,  405 
properties,  11,  311 
quality,  sampling,  12,  16 
saturated,  properties  of,  323 
specific  heat,  318 
specific  volume,  315 
superheated,  319 
total  heat,  315 
vapor  tension,  314 
work  in  steam,  318 
Steam-boiler  practice,  325 
chimney  draught,  332 
chimney,  size  of,  336 
condensers,  331 
flue  area,  capacity,  337 
flue-gases,  heat  in,  340 
fuels,  properties  of,  325,  335 
preheating  feed  water,  331 
water  supply,  327,  332 
Stoppage  of  services,  202 
Stoppers  for  mains,  167 
Storage-tanks  for  compressed  gas,  229 


466 


SUBJECT-INDEX. 


Subaqueous  pipe-laying,  cost  of,  177 
Sulphur,  compounds  in  gas,  removal 

of,  73 
Sulphureted   hydrogen  in  gas,  tests 

for,  72,  86 

Superheated  steam,  properties  of,  319 
Superheater:  carbon  deposits,  53 
checker-brick,  55 
temperatures,  53 

Tanks:    box-like,  gallons  contained, 
364 

cylindrical,  gallons  contained,  360 

storage  of  compressed  gas,  230 
Tap  and  drill  numbers,  399 
Tapping  mains  for  services,  165,  200 

high- pressure,  267 
Tar,  water-gas:  burner,  62 

composition,  58 

paint  and  pavement,  59 

pumps,  60 

separator,  61 
Technical  data,  267 
Temperature:  absolute  zero  of,  273 

air:  effect  on  saturation,  275 
effect  on  barometer,  276 

certain  industrial  ope  rat  ions,  307 

combustion  of  gases,  302 

correction  for  volume,  215 

generator,  6 

purifier-boxes,  81 

superheater,  53 

Temperature      measurement :      blue 
glasses,  300 

iron,  color  of  highly  heated,  305 

melting-points,  304,  307 

polariscope  or  lunette,  305 
Testing:  consumers'  meters,  209 

gas  ranges,  256 
Thermometer  scales,  French-English, 

373,  410 

Threads  of  screw-pipe,  382 
Tools  for  laying  cast-iron  mains,  456 

for  laying  services,  458 


Trays  for  water-gas  scrubbers,. 64 
Trenches,  gas-main:  cost  of,  169 
size  of,  146 

Units:    English    and    French,    con- 
verted, 368 

English  measures  for  water,  376 
English  weights  and  measures,  375 

Universal  pipe- joints,  154 

Valves,  strength  of  pipe,  381 
Vapor  tension:  aqueous  vapor,  275, 
278,  279,  314 

mercury  vapor,  406 

steam,  315 
Volume  of  air,  effect  of  pressure  on, 

105 
Volume  of  gases,  271 

corrections  for,  115 

effect  of  pressure 'on,  227 

Wash-box,  water-gas,  56 

Water:  analysis,  66 

calculations  concerning,  401 
equivalent  evaporation  of,  411 
flow  of,  in  pipes,  friction,  327,  329 
lift,  suction,  various  altitudes,  332 
measures  of,  conversion,  376 
supply  for  water-gas  works,  133 
weight   at    various   temperatures, 
330 

Water-gas  apparatus,  1 

Weight:  fuels,  326,  335 
gases,  various,  268,  270 

molecular,  274 
lead  pipe,  389 
malleable  iron  gas-fittings,  386 

Weighting  of  gas-holders,  123 

Weights  and  measures,  conversion  of, 
375     . 

Welsbach  burners,  260 

Work  in  steam,  distribution  of,  318 

Yarn  required  for  pipe- joints,  459 


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(  UNIVERSITY   j 

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3 


O'CONNOR,     HENRY.     The     Gas-Engineer's     Pocket-Book. 

Comprising  Tables,  Notes  and  Memoranda  relating  to  the 
Manufacture,  Distribution  and  Use  of  Coal  Gas,  and  the 
Construction  of  Gas  Works.  Second  edition,  revised. 
12mo,  flexible  leather.  London,  1903 $3.50 

PALAZ,  A.  Treatise  on  Industrial  Photometry  with  Special 
Application  to  Electric  Lighting.  Authorized  Translation 
from  the  French  by  G.  W.  Patterson  and  M.  R.  Patterson. 
Second  edition,  revised.  With  numerous  diagrams  and 
tables.  8vo,  cloth.  Illustrated.  324  pp.  New  York,  1896. 

$4.00 

PECKSTON,  T.   S.    Practical  Treatise  on  Gas  Lighting;    in 

which  the  Gas  Apparatus  Generally  in  Use  is  Explained  and 
Illustrated  by  twenty-two  appropriate  plates.  Third  edition. 
8vo,  cloth.  Illustrated.  472  pp.  London,  1841  $6.00 

POOLE,  H.    Calorific  Power  of  Fuels.    With  a  collection  of 

auxiliary  tables  and  tables  showing  the  heat  of  combustion 
of  fuels ;  solid,  liquid,  and  gaseous.  To  which  is  appended 
the  report  of  the  committee  on  boiler  tests  of  the  American 
Society  of  Mechanical  Engineers  (December,  1899).  Second 
edition,  revised  and  enlarged.  With  tables,  figures  and  dia- 
grams. 8vo,  cloth.  Illustrated.  269  pp.  New  York,  1905. 

$3.00 

PRACTICAL  GAS  FITTING.  Two  illustrated  articles  re- 
printed from  "The  Metal  Worker,  Plumber  and  Steam 
Fitter,"  describing  how  to  run  mains,  lay  pipes  and  put  up 
gas  fixtures.  With  diagrams.  12mo,  cloth.  Illustrated. 
116  pp.  New  York,  1906 $1.00 

RICHARDS,  WM.  A  Practical  Treatise  on  the  Manufacture 
and  Distribution  of  Coal  Gas.  Plates  and  illustrations. 
4to,  cloth.  London,  1877  $12.00 

SPICE,  R.  P.  A  Treatise  on  the  Purification  of  Coal  Gas. 
8vo,  cloth.  London,  1884  $3.00 

STEVENSON,  F.  W.  Modern  Appliances  in  Gas  Manfacture. 
8vo,  cloth.  London,  1901  $2.00 

WINKLER,  C.  Handbook  of  Technical  Gas  Analysis.  Second 
English  edition,  translated  from  the  third,  greatly  enlarged 
German  edition,  with  some  additions,  by  George  Lunge, 
Ph.D.  With  figures,  diagrams  and  tables.  8vo,  cloth.  Il- 
lustrated. 190  pp.  London,  1902  $4.00 


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